4.1 Early church period

Early Christianity distinguished itself from myriad religious alternatives by its twin emphases on conversion (the demand that its followers renounce all other gods than the living God revealed in Jesus Christ, see Christian Theology of Religions); and evangelization (the active effort to engage in missionary outreach). As noted earlier, New Testament writers employ the phrase ‘turned to the Lord’ to depict the conversion of Gentiles. A situation of openness to, and the general pluralism of, religious options in the Roman Empire provided a favourable context for the full expression of these convictions. Indeed, apart from occasional demands to worship the gods or emperors of the state (which resulted in sporadic and sometimes violent persecution of Christians), Roman authorities made no exclusive demands upon its inhabitants. In this environment, conversions to Christianity occurred – at first slowly: by 100 CE about 0.0126% of the population was Christian; and then after the Emperor Constantine’s conversion in 312 (the first emperor to embrace Christianity), exponentially: by 350 CE they constituted a majority of the population (56.5%) (Stark 1996: 6–7).

The modern discussion of conversion in the ancient world was offered initially by A. D. Nock, who argued that as prophetic, exclusivist, monotheistic religions, Judaism and Christianity ‘demanded renunciation and a new start’. They demanded not merely acceptance of a rite or the incorporation of another religion, as was the case with the Graeco-Roman polytheistic and assimilative religions of the day, but an individual’s ‘turning which implies a consciousness that a great change is involved, that the old was wrong and the new is right’ (Nock 1933: 14, 7). Christian conversions meeting Nock’s criteria may be found among the educated elite such as Justin Martyr, Tatian, Arnobius, Cyprian, and Gregory of Pontus – though it must be acknowledged that they did not so much completely replace something old with something new as transform existing categories by giving them new meaning. For example, both Justin and Tatian, thoroughly immersed in Greek culture, understood their conversions as the culmination of philosophical quests. In his search for true wisdom, Justin met an old man who urged him to read the Jewish prophets who ‘alone knew the truth […] and made known Christ’ (Dialogue with Trypho 7; Justin Martyr 1948: 160). Justin did so and concluded that Christ was the true Logos understood dimly by the ancient philosophers as an idea but now fully known in the incarnate Christ. Similarly, after encountering ‘barbarian writings’ (the Old Testament), Tatian is ‘taught by God’ and is led to the New Testament and Christ (Discourse to the Greeks 29; Tatian 1982: 55). Both Justin and Tatian were thoroughly disillusioned with Greek culture (they vociferously attack ‘demons’, the recognized lesser divine powers of the universe), and yet they used the existing structures of thought to express their turn to Christianity.

Because educated Christians were so few and illiterate Christians so many, Ramsay MacMullen contends that the masses, after witnessing displays of divine power, came to faith simply by crying out, ‘Great is the God of the Christians’ (MacMullen 1984: 41). Jesus worked miracles and exorcised demons; so did his first disciples and Christians well into the second century. With hundreds of gods and hundreds of choices, Christianity won over ordinary people by driving out the competition. Origen observed that exorcisms ‘lead many people to be converted to God, many to reform themselves, many to come to faith’ (Kreider 1999: 17). In twenty-two of twenty-nine conversion stories, the Apocryphal Acts of the Apostles (second and third centuries) highlights miracles as a stimulus to conversion, although to be sure, these stories are exaggerated and fanciful (Gallagher 1991).

The prevalence of miracles as inducements to conversion cannot be discounted, but other factors also came into play. First, in a period when mortality rates were exceedingly high among infants and children, and when about half of those who lived to the age of fifteen died by age fifty, Christianity offered the hope of immortality. For Christians, death meant the beginning of another life, not the fading into the netherworld of disembodied souls. Second, the behaviour of Christians toward others through acts of mercy (almsgiving) and the offer of a sense of community, caring, and belonging attracted others to the faith. Third, Christianity cut through the countless options in the ancient world, offering a coherent system of beliefs and practices. Christians announced there was one true God, Lord, and Creator of the universe who was more powerful and personal than the gods and idols of the pagans. Fourth, in some cases, the example of Christian martyrs attracted potential converts.

The overwhelming scholarly consensus is that conversions flowed along the lines of social networks, personal encounters, and especially friendships (Lane Fox 1987: 316; Stark 1996: 13–21). Moreover, the initial turn to Christianity was followed by a long process of instruction and moral renovation, culminating in baptism and incorporation into a new community. In early third-century Rome, converts were screened before they were permitted to take instruction. The screening continued during a three-year period of instruction and regular exorcisms and concluded with baptism on Easter morning (Apostolic Tradition; Bradshaw 2002; see also the Didache; Jefford 1995). This lengthy training was viewed as necessary so that converts might deepen their initial conversion by understanding the content and ethical demands of the faith.

In the ancient world, conversion affected individuals but was not understood as a private, individualistic turn as it is often viewed in the modern world. Rather, individuals converted but they viewed their conversion in collective terms. Conversion was thus a social process of reordering or rupturing relationships with family, friends, fellow workers, and even state power. In the second century, Justin Martyr described the convert’s community as a ‘new race’ (ethnos), suggesting that the converted are members of a universal race of the redeemed who have exchanged one race or nation or people for another (First Apology 23; Justin Martyr 1948: 59). Regardless of one’s race (i.e. nation or people), all could become members of a universal race, people, or nation – all could become one in Christ Jesus (Gal 3:28).

Prior to Constantine’s conversion, Christians encountered sporadic resistance both from state authorities and a hostile populace; following his conversion, they received state support and popular acceptance. With this privileging of Christianity, the meaning of conversion and the level of Christian commitment changed in significant ways. The Council of Nicaea raised concerns over the rapid ascent of former pagans to positions of church leadership, and many church authorities reported hasty, superficial, opportunistic conversions. Augustine lamented those who wished to become Christians ‘with counterfeit motives, desirous only of temporal advantages’ (First Catechetical Instruction 1.5.9; Augustine of Hippo 1952: 24, 25).

The means by which conversions occurred also changed. Whereas in the pre-Constantinian period, conversion was followed by a lengthy catechumenal process and baptism, in the fourth century this process was shortened and the order was often reversed. Through an elaborate and dramatic baptismal ceremony that mimicked initiation rites into mystery religions, church leaders anticipated that conversions would result after which the converted were given deeper instruction in the faith (mystagogy). In his Catechetical Lectures, Cyril of Jerusalem enjoined a process of screening candidates who would undergo an eight-week period of instruction and exorcism. The moment of conversion came with baptism when something was done to rather than by the initiate (Telfer 1965).

In his Confessions, Augustine narrates a considerably different type of conversion, exceptional in the ancient world for its personal intensity and profound insights into the soul’s quest for God. Indeed, the highly personal and emotional evocations in the Confessions became a paradigm for Christian conversion in the modern West. Although there was a shattering moment in his life (the Milanese garden scene in Book 8), it is clear this crisis was the culmination of a series of intellectual and theological turnings influenced by his Christian mother, the reading of scripture, hearing stories of conversion, Neoplatonist philosophy, the influence of friends, and the teachings of Ambrose. His conversion to Catholic Christianity was at once a turning from ‘the gnawing anxieties of ambition and gain, from wallowing in filth and scratching the itching sore of lust’ (9.1; Augustine of Hippo 1971: 181) and a turning to a love of the Good: ‘You [God] converted me to yourself’ (8.12; Augustine of Hippo 1971: 179).

4.2 Medieval period

Although an absence of information about pre-Christian traditional paganism makes it difficult to know what people converted from, Christian conversion in its medieval context connoted multiple understandings of conversion: (1) acknowledging a more powerful God than pagan gods; (2) the adoption of a creed and the acceptance of church authority; (3) forced acceptance; and (4) entry into the ascetic life of the monastery.

The medieval period marks a second stage of ‘tradition transition’ conversion. Along the missionary frontiers in Europe, the great masses of people who converted were illiterate and impoverished. As Richard Fletcher notes, ‘[t]he spectacle of early medieval conversion to Christianity […] is generally not one of individuals acting upon conviction’ (Fletcher 1998: 514). Introspective or dramatic conversions are very rare and, in most cases, limited to the monastery. People became Christians because they were told to or were born into the faith. Consequently, their conversions (equated with the sacrament of baptism) were often superficial. Despite the heroic efforts of missionary monks and bishops, the often insuperable difficulties of language, staffing, and institutional presence resulted in nominal conversions.

Two famous letters from Pope Gregory I (written in 601) regarding evangelistic strategies in Kent indicate two approaches toward conversion that would vie with each other throughout the medieval period. In the first letter, he encourages King Ethelbert to follow a course of intimidation and suppression: ‘redouble your righteous enthusiasm’ in the conversion of your subjects; ‘hunt down the worship of idols, and overturn the building of temples’, by pious example, terror, and flattery (Gregory I 2004: 783 [vol. 3]). The second letter, written to Abbot Melitus, reverses his policy of coercion for one of accommodation and cooptation. He asks Melitus to tell Augustine ‘what I have long pondered over’. Gregory instructs the missionary party not to destroy a pagan temple, but to destroy its idols and consecrate the temple for Christian use, for ‘it is certainly impossible to eradicate all errors from obstinate minds at one stroke’ (Gregory I 2004: 802–803 [vol. 3]). Although Gregory’s policy of accommodation may have proved more effective in producing authentic conversions to Christian faith, it also had the potential to lead to superficial conversions. According to James Russell, the so-called conversion of Germanic peoples (c. 750) often meant little more than the embrace of a magico-religious cult of a powerful deity whose actions were conceived very much like that of a contemporary despotic emperor (Russell 1994: 198). Over the centuries, a process of Christianization and increasing conversions occurred, but pagan religions and Christianity coexisted in parts of Europe well into the eighteenth century.

Three conversion themes are prominent in the early medieval period. First, those targeted for conversion were often leaders. Missionaries recognized that in pagan societies political power included control over the religious realm. Religion was essentially a communal affair rooted in ancestral custom. If leaders converted and had the support of their military elite, their subjects would follow. In the well-known conversion of the Merovingian King Clovis, 3000 of his troops followed him in baptism (Gregory of Tours 1979: 2.30–31 [pp. 144–145]). In England, the conversion of King Ethelbert marked the beginning of a series of royal conversions in the seventh century (often due to the influence of the queen consort). Edwin of Northumbria favoured Christianity but hesitated to commit until after he obtained support from his high priest of the old religion and other leaders. Once they confirmed the power of the Christian God over the old gods, the king, ‘with all the nobility of his kingdom and large number of humbler folk, accepted the Faith and were washed in the cleansing waters of baptism’ (Bede 1968: 2.14 [p. 128]). With royal support and protection and papal instruction to guide them, missionaries set about their task of preaching and converting the populace.

A second conversion theme emphasizes the two-fold means by which people were converted, namely, through persuasive preaching (about which little is known) and displays of miraculous power (which abound in written sources). Sulpicius Severus’ Life of St. Martin (d. 397), a model for subsequent hagiographies and conversion stories throughout the medieval period, reports Martin preaching ‘Evangelical truth’, although most of the Life is replete with tales of people coming to faith through Martin’s performance of miracles (raising a dead man, exorcising demons) or miracles performed on his behalf (such as God miraculously diverting a falling pagan tree after Martin, in a test of faith, agrees to stand in its falling path; see Severus 1952). A third conversion theme highlights the transformation of the physical landscape. When pagan temples and shrines were destroyed and replaced by churches and chapels, or pagan temples were turned into churches, or burial grounds were Christianized, or Christian rune stones replaced pagan ones, people turned to Christianity.

The formula for forced conversions in the Middle Ages was the potent combination of exclusive claims to the truth advanced by warrior kings in an already violent society and the Old Testament model of kingship that included wiping out the enemies of Yahweh. This practice, traceable to the fourth century with the rise of imperial Christianity, was endorsed initially in dealing with non-Catholic Christians (e.g. Donatists and Arians). It was then applied sporadically to Jews. In 576 at Clermont, for example, five hundred Jews converted following the destruction of their synagogue by a Christian mob and Bishop Avitus’ ultimatum of conversion or exile. This method of conversion was most evident among the Carolingians, especially during the reign of Charlemagne (768–814): as one contemporary commented, Charlemagne preached with ‘an iron tongue’ by exacting forced baptism of the conquered Saxons and Avars in the last quarter of the eighth century (Sullivan 1994: 277).

The eleventh to the fourteenth centuries witnessed the increasing acceptance of forced conversions of Jews in the Iberian Peninsula, and of pagans in the northern regions of Europe that remained unconverted – Scandinavia and the Baltic. The degree to which forced conversion is authentic raises questions about the meaning of conversion. Have a subjected people under threat of death become Christian when a priest sprinkles water over them and says some words in Latin? Charlemagne would say yes; but Alcuin, the scholar/abbot in his court, said no, and urged pre-baptismal instruction of Christian creeds and morality before declaring anyone a Christian convert.

Another and more precise understanding of conversion occurred in the context of monastic calling. As early as the end of the fourth century, the concept of conversio became increasingly identified with asceticism and monastic living. In his Rules (sixth century), Benedict of Nursia refers to conversion in two ways: the act of becoming a monk and the monastic life itself (Benedict 1975). The popular genre of ‘harlot lives’ conveyed the ideal convert as a woman who embraced the ascetic, celibate life of a hermit (Ward 1987). Augustine’s conversion marked a repudiation of sex and a commitment to the monastic community. By the fifth century, baptized persons who rejected the lures of the world and gave themselves wholly to serving God in the monastery were said to ‘convert’. Especially in areas where Christianity was coextensive with society, conversio came to denote this turn to the monastery and the lifelong process of spiritual renovation, especially the inner spiritual practice of ‘taking up penance’. Bernard of Clairvaux identified conversion with the pangs of conscience, remorse, and a broken spirit (conversio morum) – the kind of divine knowledge acquired only in the monastery (Bernard of Clairvaux 1971–1980). Within mendicant orders, conversion meant less of an outward change of behaviour and more a change of heart that propelled members to pursue the via apostolica (‘apostolic way’) in the world. The flowering of mysticism in the thirteenth and fourteenth centuries reinforced this understanding and spread to other monasteries and beyond into lay communities such as the Brethren of the Common Life and the Lollards (Van Engen 2003). This deeper understanding of conversion, with its built-in critique of conversion as merely affiliation (i.e. affirming and identifying with the externals of the church: its laws, doctrines, and rituals and all the ‘christened’ community of medieval Europe), potentially subverted and challenged the status quo.

4.3 Reformation and early modern period

Early evangelicals were late medieval Christians and, as such, the views of conversion mentioned above extended into the Reformation era among both Protestant and Catholics, with both sides claiming that their earlier conversions were not authentic conversions. Evangelicals derived their views of conversion from a new understanding of scripture. Martin Luther felt he ‘was altogether born again’ after his theological breakthrough regarding justification by faith (Luther 1961: 11). Others reaffirmed the biblical link between conversion and repentance. John Calvin described a process of gradual awakening and repentance from devotion to the ‘superstitions of Popery’ to that of a culminating experience: ‘God by a sudden conversion subdued and brought my mind to a teachable frame’ (Calvin 1975: 26). Furthermore, in his New Testament translation, William Tyndale departed from the Catholic sacramental translation of metanoeo (‘do penance’) and replaced it with ‘repent’ (see Tyndale 1989: 119).

Conversion for early Protestant reformers hinged on an inward turn of constant self-examination and affirming a new theological direction. Luther’s views epitomized the connection to a Catholic past and the direction of the Protestant future. He understood conversion in several ways: an unrepeatable mystery of entrance into the Christian life in baptism (conventional Catholic view); a repeatable event of contrition and penitence (the monastic view); and an event of dramatic personal transformation such as his ‘tower experience’, which clarified his understanding of justification (emerging Protestant view; see Harran 1983). The latter, recalled Luther, defined his turn from Catholicism and would put him at odds with church and political authorities. Indeed, among first generation Protestant reformers, conversion to the evangelical message often brought calamitous consequences, even death for the crime of heresy (i.e. resistance to re-conversion).

Catholic reform movements (e.g. the Jesuits), but especially Protestant evangelical movements, emphasized the necessity of conversion defined as an introspective process characterized by a heart-felt, personal appropriation of faith. German Pietists located true religion in the heart, that is, in the will and affections (or ‘dispositions’). Their language of ‘rebirth’, ‘regeneration’, and ‘new man’ stressed the subjective, experiential, emotional, even mystical side of conversion. John Wesley’s exposure to Pietist Moravians culminated in his famous conversion which he described as his heart being ‘strangely warmed’. Puritans, although attuned to the inscrutable mystery of God’s sovereign purposes, developed psychological stages of conversion (morphologies) whereby conversion was understood as not only a key event but a life-long process of turning to God. In North America, this attention to stages or signs culminated in Jonathan Edwards’ Religious Affections wherein he charted biblically rooted ‘signs’ (and ‘no signs’) indicative of genuine conversion.

Increasingly in the West, and particularly in the United States, an understanding of the self as an individual, autonomous and capable of making independent choices, influenced views of conversion. Most notably, evangelical forms of Christianity emphasized the necessity of a conscious, datable, ‘born again’ conversion – the very kind that most interested William James and influenced conversion studies up until the 1960s. Indeed, James, whose views influenced Nock, described the archetypical conversion as a soul-shattering crisis and all-consuming process of the ‘twice-born’ or ‘re-born’ type (James 1902).

Although the evangelical model of conversion remains predominant, other models of ‘turning’ persist (Peace 2004). Among historic forms of Protestantism (e.g. Lutheran, Presbyterian) where Christianity has had a cultural presence, conversion is understood as a process of socialization. Within these traditions, parents present their children for baptism and the children are raised in a Christian milieu; at some point, as an adult, the children commit to the Christian community. There may be moments where Christian commitment is reaffirmed – however, little emphasis is placed on the stark contrast that is found in evangelicalism between a conscious unconverted and converted condition. Within liturgical traditions, the moment of conversion begins with the sacrament of baptism. For example, ‘Cradle Catholics’ and ‘Original Orthodox’ believers are ‘born into’ or ‘baptized into’ the faith rather than ‘born again’ in an evangelical sense. These traditions, however, have their share of dramatic adult conversions, including intra-conversions. Moreover, there have been renewed efforts to affirm the importance of conscious conversion. The Catholic Church’s Rite of Christian Initiation of Adults is a designed catechumenal process that seeks tangible and profound conversions (Gelpi 1998). Also, recent theological attention to conversion has emphasized a holistic dimension of conversion whereby an initial turn to Christ extends beyond personal benefits to a concern for justice and love of neighbour (Wallis 2005).

In the United States, where a free market of religious choice predominates, some ‘born again’ evangelicals discovered what was for them a more satisfying Christian tradition in Roman Catholicism, Orthodoxy, or Anglicanism. Their desire for rootedness in tradition, the mystery of sacramental worship, and an emphasis on traditional disciplines of the Christian life have resulted in ‘institutional transitions’ – conversions from one Christian community to another (Herbel 2013; Plummer 2012; Slagle 2011; Webber 1985).

4.4 The early modern and modern periods on the global stage

From its beginnings, Christianity was a missionary movement and global in character. As such, it is mistaken to characterize Christian expansion as solely a modern phenomenon. Nevertheless, the last 500 years have been marked by Western Christianity’s expansion beyond Christian Europe to the Americas, Asia, and Africa – indeed, to virtually every corner of the globe. Thanks to sea-faring nations such as Spain and Portugal, Catholicism encircled the globe by 1600. For a variety of reasons, Protestantism was slow to expand beyond the confines of its European territories, but by 1900 it challenged Catholic dominance.

This third great shift of cross-cultural movement into the Global South presented formidable challenges in communicating the Christian message in categories understandable to people on their terms. Scholars have employed a variety of names to describe the nature and type of conversion in non-Western environments: enculturation, indigenization, hybridity, contextualization, accommodation, absorption, translation, assimilation, and (pejoratively) syncretism. Each of these descriptors carries its own specific meaning; but collectively they point to the degree of complex interaction between European Catholic and Protestant views of conversion within which were embedded assumptions about ‘normal’ conversion. In this process of cross-cultural interaction, not only were converts made but missionaries often readjusted their own thinking about what made converts and constituted conversion.

In colonized regions such as Latin America, the earliest efforts to convert Indigenous peoples assumed a model of territorialism. Typically, forced conversions followed brutal conquest. Missionaries erected public places of worship, planted crosses, and sacralized the landscape in other visible ways while attempting – largely unsuccessfully – to extirpate all vestiges of indigenous ‘idolatry’. The depth of Native American conversions was as varied as the methods used to produce them. On a superficial level, conversion meant a transfer of loyalty or allegiance, often without knowledge of what that transfer entailed. Or, with defeat, it might represent a conscious acknowledgement of the more powerful Christian God over weaker traditional deities. Amid the destruction of native cultures and coerced conversions, the Dominican Bartolomé de las Casas (d. 1566), the most vocal critic of colonialism in this era, argued that people are won to Christ through love and compassion (Las Casas 1992). His pleas were largely ignored in his day.

In the North American context, Jesuit missionary efforts in the seventeenth century among the Mohawk (a tribe within the larger Iroquois confederation) reveal an accommodating approach toward conversion. Under the guidance not only of the Jesuits but of their own people, who gave instruction and led prayers and singing, the Mohawk incorporated elements of Christianity into their spirit world. For example, the concept of the Trinity fit easily into their cosmos of many divinities. Black robed Jesuits appeared as powerful shamans. Just as ritual formed the basis of North American Indigenous religions, so the Mass, confession, baptism, and last rites underlay Native American Catholicism. In some cases, traditional elements of Mohawk life remained untouched or ignored by Jesuits, such as Mohawk festivals and rituals of thanksgiving. In yet other instances, the Mohawk maintained traditional practices that contradicted Christian teaching. Dream divination, curing rites, and sun worship remained features of Mohawk life. Thus, traditional Native American approaches toward reaching the sacred and securing divine favour existed alongside Christianity. In this dynamic process of encounter and engagement with foreigners, the Mohawk accepted Christianity on their own terms (Greer 2003).

Different challenges confronted sixteenth-century Jesuit missionaries who entered China without political power or the force of arms. They came as supplicants seeking to be heard, and, while they assumed their religion was superior to other alternatives, the more culturally sensitive among them, such as Matteo Ricci, soon learned that without immersion in the thought forms and practices of the literati and mandarin, they had little chance of attracting converts. Employing a ‘top-down’ strategy, Ricci networked with high officials, studied Confucian texts, and participated in discussions with Confucian scholars in hopes of winning converts. Other Jesuits pursued a ‘ground-up’ strategy to rural inhabitants, analogous to that employed by earlier missionaries of demonstrating that the Christian God (‘the Lord of Heaven’) was more powerful and efficacious than the spirits or deities native to the land (Hsia 2010). Still others used visual objects (e.g. a devotional painting of Christ) as a cultural bridge, seeking to connect Christianity to the proliferation of Buddhist or Daoist images. For most Chinese converts, the inward psychological paradigm of Christian conversion and Paul’s description of how the Thessalonians ‘turned to God from idols’ (1 Thess 1:9) were totally absent; they simply incorporated their new faith alongside Buddhist and Chinese statues. The Chinese treated Christian objects as they did their own, believing in their magical powers to ward off evil, heal the sick, and drive away demons. To claim that there was a single true God, or that one should attend one place of worship to the exclusion of others, simply did not fit the Chinese understanding of the role of religion in everyday life (Brockey 2007).

As scholars have recognized, China was not primarily evangelized by missionaries who introduced Christianity to China, but by the Chinese themselves (Tiedemann 2008; White 2017; Lee 2013). For example, nineteenth-century Chinese Protestants in Chaozhou (south China coast) spread the faith through native kinship, lineage, and village networks, integrating the gospel into the moral and cultural fabric of Chinese society. Previously evangelized by Scottish Presbyterian and American Baptist missionaries, they drew from existing patterns of thought to indigenize their understanding of Christianity. In one of their hymns, they drew on a Buddhist worldview to link sin with bad karma and in Jesus’ ability to negate one’s moral failings. In another hymn, they identified ethical values shared by Christians and Confucian scholars in recognizing Jesus as the guardian of the heavenly mandate and a virtuous man who suffered for others. Chaozhou evangelists challenged spiritual mediums to demonstrate the power of Jesus. Through prayer and by invoking the name of Jesus, they performed exorcisms, casting out harmful spirits and demons. Theirs was not a superficial adaptation of Christianity from the West but the creation of a truly indigenous Christian movement (Lee 2013).

In Africa, where primal or basic religions predominated, conversions resembled the ‘power conversions’ of the early church. Palpable divine encounters, be they visionary experiences or supernatural displays of healings and exorcisms, became the primary means for the conversion of thousands of Africans. At the same time, many African converts retained traditional practices such as polygamy, divination, animal sacrifice, and the veneration of ancestors (Bediako 1995; Kalu 2008). Scholars have advanced materialist and instrumental explanations of Christian conversion, arguing that Africans converted not because they were convinced of the gospel but to achieve other goals: status, wealth, education, power, health, and similar such advantages (Engelke 2004). One cannot discount these motivations, but to stress them in isolation neglects the ways Africans themselves interpreted and appropriated Christian scriptures, practices, and institutions for their own purposes, and within the context of their own needs and values (see Theology in Africa). For example, William Wade Harris (c. 1860–1929), the first of numerous prophetic African leaders to emerge in the early decades of the twentieth century, and the single greatest evangelist in African history, developed his Christian views within the context of an African worldview that affirmed a sacramental universe wherein spiritual forces inhabited all of nature. Harris underwent several conversions, the last in which he experienced a trance-visitation by the angel Gabriel and the anointing of the Holy Spirit. By divine command, he abandoned his European clothes and dressed in a white robe and turban. Called to be a prophet and evangelist, Harris carried a cross-topped staff, Bible, calabash rattle, and baptismal bowl. He attacked local spiritual powers and called for repentance and the destruction of all idols. His immediate success as a faith healer and exorcist soon attracted thousands, resulting in a multi-ethnic mass revival that spread throughout the southern Ivory Coast, today called Côte d’Ivoire (Shank 1994).

Harris’ prophetic movement and others that followed were precursors to the contemporary Pentecostal movement that, since the 1970s, has inflamed the continent. With its openness to the supernatural, Pentecostal conversions resonate with African piety in three ways. First, with an emphasis on transformation that comes through the empowering presence of the Holy Spirit, Pentecostalism offers a reconstructed life at both the personal and social levels. The conversion experience is the foundational doctrine of all Pentecostal churches. Second, Pentecostals conceive of divine power primarily in pragmatic terms, offering a theology of empowerment to defeat ever-present malevolent forces represented by those with evil eyes, demons, witchcraft, curses, and misfortunes of various kinds. Finally, the transformative and empowering aspects of Pentecostalism pave the way for good health, success, and prosperity in life. Conversion offers real-world benefits (Asamoah-Gyadu 2007).

In India, as in China and in Africa, the missionary presence was a necessary but not sufficient factor in Christian conversions. Missionaries initiated the first conversions, but, within a generation or two, Indian Christians became the primary instruments for the spread of the gospel. Communication never flowed in one direction; increasingly, Indians converted on their own terms and adapted Christianity to meet their own concerns. Among nineteenth-century upper caste converts, Krishna Pillai (1827–1900), who became a famed Christian Tamil poet and hymnwriter, incorporated the popular Hindu term Saccidananda as the name for the Christian God. In Sanskrit, the word is made up of three terms: Sat (‘existence’; God does not change), Chit (‘knowledge’; God is the mind behind the universe), and Ananda (‘joy’; God is the abode of bliss). Toward the end of his life, Narayan Vaman Tilak (1861–1919) adopted the life of a Christian sannyasin (ascetic) – the last of the four stages in Hindu life (Appasamy 1966). Other converts such as Pandita Ramabai (1851–1922) identified with Western forms of Protestant Christianity; but when missionaries criticized the girls at her Mukti Mission for their emotional outbursts and speaking in tongues, Ramabai responded, ‘Let the revival come to Indians so as to suit their nature and feelings’ (Kim 2011: 27)

Upper-caste conversions represent only a small fraction of Indians who adopted Christianity as their faith. Christianity’s attraction has been and remains among the masses, the ‘subordinate classes’ of the poor, the outcaste, and the underprivileged. Group conversions, often motivated by the desire to escape from upper-caste oppression, extend beyond Christianity to include mass conversions to Islam and Buddhism. (The most famous of these occurred in 1956, when 600,000 low-caste Indians abandoned their caste and took Buddhist vows.) Since all social groups were defined by caste, and since one’s identity was defined by the group rather than by one’s individuality, group conversion (as opposed to the individualistic emphasis of evangelical foreign missionaries) was a more natural way to become Christian.

The catalyst for these mass movements into Christianity were Indians, not foreign missionaries. For example, among the Chuhras of the Punjab, beginning in the late nineteenth century and continuing into the 1930s, group conversion was initiated, transmitted, and sustained at the grass-roots level by Dalits (formerly called ‘untouchables’) themselves. Chuhras converted en masse for several reasons, largely because Christianity addressed a variety of needs and embraced the whole person. Beyond the spiritual benefits (e.g. immediate access to salvation), Christianity also addressed the needs of the body (improved health and hygiene) and the mind (educational opportunities). The ideal of egalitarianism in Christianity (‘all are one in Christ Jesus’, as in Gal 3:28) challenged Hindu social customs and led to a new identity (Cox 2002).

5.1 Human cognizance of divine presence

Whether or not the reader believes in the intervention of God or the supernatural, those who are aware of their own religious transformation, as well as those who promote Christian conversion, often attribute the change to divine intervention. In the Christian view, God is love, and as such God seeks a direct relationship with people. For Christians, God communicates in palpable ways: audibly (hearing the voice of God), visibly (having dreams, visions, or trances), vocally (uttering Spirit-inspired speech), and sensibly (being aware of spiritual power). Christ is physically, sensually present – seen, heard, or felt in dreams or visions. The Holy Spirit is bodily present in shrieks, groans, and convulsions. Miracles occur, the greatest of which is the conversion of the soul to God. The display of these phenomena is particularly manifest in conversion narratives (whether first- or secondhand). In other, indirect ways, the living God becomes real to people – even to modern people (see below, 5.15). People convert to Christianity; they change, and the attribute their transformation to God.

5.2 Context

The conversion process is shaped by the intersection of larger historical frameworks (i.e. political, religious, institutional, and socioeconomic structures) interacting with the personal, localized context of family, community, work, and everyday experience. As much as William James (1902) promoted individual conversion as a transhistorical phenomenon, the process and meaning of conversion changes in different historical contexts as part of other historical transformations. Through spoken words, gestures, and writings, advocates of conversion communicate a particular view of conversion. These advocates – friends, families, missionaries, evangelists, or theologians – often serve as models of conversion or the vanguard of a new way of understanding conversion. Because of their efforts, communities may form and further elaborate and convey the meaning of conversion, reinforcing salient beliefs and formulating a shared vocabulary, behavioural guidelines, and ritual expressions.

5.3 Continuity and discontinuity

How much of the new displaces the old in Christian conversion? In cases of ‘tradition transition’, in which an individual converts from a major religious tradition (e.g. Hinduism, Buddhism, Confucianism), a vast cognitive, cultural, and religious chasm separates the old from the new. The more developed and entrenched a major religion, the less open individuals are within that religion to converting to Christianity (and vice versa). Within Christian contexts, the distance is considerably shortened, where conversion may mean a revitalized or intensified commitment to the Christian faith.

The process of conversion may entail a substitution, or an abandonment, or a transformation of old beliefs, behaviours, and practices. Where Christianity has made a lasting impact, however, the conversion process is one of transforming existing structures, not refuting them by foreign imposition.

5.4 Nominal, incomplete, and ‘true’ conversion

A persistent and controversial issue within the history of Christian conversion is the call for ‘true’ conversion by those who judge that tepid, nominal, or wrong-thinking forms of Christianity demand a higher commitment or a new understanding. Conversion thus potentially subverts the status quo. ‘Who are the real Christians? Who are the truly converted?’ resounds throughout the history of Christianity, particularly in reform or spiritual awakenings where strident voices demand the separation of the converted wheat from the unconverted chaff.

5.5 Personal testimonies and narratives

The autobiographical impulse attests to the converted life; the old has passed away and the new has come. Testimonies draw a stark polarity between ‘before’ and ‘after’; a departure from a previous life of ungodliness, idolatry, lust, worldly pleasure, and misplaced priorities to a new life redeemed by the power of God. Testimonies situate the convert’s personal story or narrative within the larger Christian story or metanarrative, thus giving purpose or significance to what has transpired. If written, they are often stylized reconstructions of events and thoughts; if oral, they may be more spontaneous, and yet, if delivered repeatedly, they too will become stylized, conforming to the expectations of the convert’s community. This impact of written narratives (accelerating with the age of print and digital media) and public testimonies of conversion cannot be overestimated for they personally legitimize or existentially validate the transformed life. ‘This is how my life has changed’ becomes ‘this is how your life can change’.

5.6 Gender

For men and women, the process of conversion often discloses the gendered roles or expectations of a religious community or culture. Complicating the relationship between conversion and gender is the fact that both change over time and place. Three aspects of gender merit observation: the advocates of conversion, the experience of conversion, and sex ratio of converts. Of course, both males and females have played active roles as advocates of conversion, but in some cases, female advocates stand out because their actions challenge conventional gender norms. For example, in the early medieval period, aristocratic women played a crucial role as advocates in the conversion of their sons, husbands, and relatives. In Latin America, beginning in the 1980s, many men converted because of being healed at a Pentecostal service to which their wives had taken them (Brusco 1995).

For a variety of reasons, more women than men convert to Christianity. Early Christianity attracted more women than men, although in general, aristocratic women converted due to the influence of fathers, husbands, or sons – those responsible for the religious life of the family. Early Methodism in England gathered a majority of female converts, as has Pentecostalism on the global stage. Since the nineteenth century, Protestantism in China has attracted an overwhelming number of women (by some recent estimates, over seventy percent; see Aikman 2006; Lutz 2010).

5.7 Identity and the self

Until the modern period – which is to say, throughout most of human history – the social unit, not the individual, defined one’s identity. Conversion typically took place within a social context of family and community, clan and tribe. Most who became Christian were illiterate. Their conversion was a conversion of practice and conduct, less so belief. To be sure, the conversion narratives of Paul and Augustine convey individual expression with heavy theological content, but they represent the exception rather than the rule. One may detect autobiography in the writings of several late medieval figures, but not in the modern sense of exploring the life of a unique individual or personality. Protestant reformers cracked open the door of self-expression, and by the late sixteenth century the genre of spiritual autobiography appeared among Puritans and Dissenters. By the eighteenth century, autobiographical conversion narratives reveal a new understanding of the self. The sense of individuation, the placing of one’s own unique history within the larger plot of redemptive history, the giving voice to the experience of God’s work in the soul, and indeed, the validity of human experience as proof positive of this divine work – these are indicative of the rise of a distinctive self-awareness or consciousness of human agency. Missionaries from the West introduced these notions on the global stage. In China, India, and Africa, the modern conception of the individual person was integrally related to the missionary project of conversion. Nevertheless, in countries and regions where traditional communities remain the determinative definer of identity, group conversions, such as among the lower castes in nineteenth and twentieth century India, continue.

5.8 Agency

Related to identity and notions of the self is the problem of agency. Although this issue is one that runs throughout the history of Christian conversion – for example, consider the great masses of converts in the early Middle Ages who submitted to or accepted the Christian faith – it has become particularly contentious among scholars in the context of Western colonialism. Under structures of colonial power, were converts actors or were they being acted upon? This much is clear: where missionary imposition and control predominated, Christianity foundered. In colonial settings where local agency predominated (e.g. with catechists, ‘Bible women’, teachers, and lay preachers), Christianity flourished. Under conditions of indigenization and local initiative, converts were not merely passive recipients of the missionary message, nor were native assistants merely collaborators in the missionary enterprise. Their role and interaction with missionaries was dialectical, dynamic, ongoing, and sometimes fraught with tension. For example, in India, low caste groups initiated and transmitted conversion movements. In modern Africa, Africans principally sustained Christianity. The encounter with African beliefs was a dynamic two-way process of reinterpreting, reassessing, and selectively assimilating the form and substance of missionary Christianity, fashioning it into an Africanized Christianity.

5.9 Mechanisms and motivations

The mechanisms behind and the motivations for converting to Christianity depend largely on who is telling the story – the convert, the advocate, or the scholar. For most of Christian history, converts’ accounts of conversion are absent; sources are thin or nonexistent. Archaeological and epigraphical evidence provide clues, and secondary accounts – which come primarily from advocates – provide insight in the conversion process, but largely from a providential perspective. Not until the age of print do conversion accounts abound (and overwhelm). Scholars approach these materials from a variety of methodological and theoretical perspectives, seeking to amplify or explain the motivations and experiences beyond what converts themselves or their advocates communicate about the nature of conversion. Some approaches are reductionistic, construing conversion as a compensatory response to material deprivation, suffering, evil, and other such conditions. Other theoretical and historical approaches recognize the limits of all-encompassing explanations and either withhold judgment about the nature of the convert’s experience, or admit there is something more to conversion than historical, sociological, and anthropological explanations allow. From this perspective, conversion occurs within a cultural setting but cannot be reduced to merely an expression of culture.

Throughout this article, multiple and often interrelated factors have been cited as motivations for people turning to Christianity. To be sure, although the fundamental theological or biblical message of conversion is turning in faith to Christ, or recognizing the power of God, or embracing the Christian story, people’s motivations to convert are not purely spiritual. Why then do people convert to Christianity? Apart from forced conversions, and with the recognition that there are some conditions in Christian conversion where choices may be limited, people convert because they sense that Christianity not only meets basic human needs but also does so in a more convincing manner than existing alternatives.

Where conversion occurs in Christian contexts as spiritual renewal or a change in affiliation, converts conclude that a particular form of Christianity is better able to meet their needs than the existing form of Christianity. Whatever the context, converts turn to Christianity for multiple reasons (and for the same reasons, they may reject Christianity): new meaning; a new way of life; a moral map; a sense of dignity and hope; a source of social change; the truth for which they were seeking; an opportunity for material improvement; an enhanced socio-economic status or access to levers of power; a sense of belonging; a solution to conjugal or family problems; protection from malignant spirits; the comfort of a loving God; the assurance of a more powerful God than other deities or spirits; the possibility of being healed; and the promise of eternal life.

5.10 The body

Conversion involves more than the mind, more than mental assent, and more than an interiorization of the faith. Throughout the history of Christianity, the body has been a site of conversion. In some cases, physical expressions lead up to the event of conversion, whereas in others, they are a part of the converting process. In late antiquity, the elaborate rite of baptism in Cyril’s Jerusalem church became a means of eliciting the profound experience of conversion (Finn 1997). In the medieval world, there was a physicality to conversion for men and women alike, although it was experienced more predominantly among women. This physicality ranged from the standard ascetic practices of the monastery to imitating the passion of Christ and the lives of the apostles to (among women) bodily nurturing. Physical pain and suffering, whether through illness or self-induced by fasting and self-flagellation, or bodily wounds (e.g. the stigmata) or emissions (e.g. copious weeping) defined the condition of the truly converted.

During America’s Great Awakenings, the sermons of Jonathan Edwards, George Whitefield, Charles Finney, and African American preachers elicited somatic responses of ecstasy, joy, and release. Once filled with fear, shame, and guilt, the newly converted shouted, cried, and fell to the ground under the inspiration of the Spirit. In India, the body as a site of conversion was expressed by upper caste male converts who cut off the sacred lock that identified their twice-born status, or by the mass conversions of former untouchables who rejected the idea that caste was a matter of blood or race.

5.11 Music

Music frequently plays a critical role in conversion, lifting the singer or observer to new spiritual heights, both drawing people to the faith and reinforcing one’s Christian commitment. Charles Wesley composed hymns commemorating his own conversion and wrote hundreds of others designed to lead sinners down the same conversionary path. The pervasive use of hymns in the evangelical tradition became an effective conversionary stratagem, triggering strong emotional and even physical reactions. Music played an important role in converting California Native Americans to Roman Catholicism. Choristers, led by Franciscan priests, were at the forefront of those who converted (Sandos 2004). The Moravian ‘Litany of the Wounds’ and the Punjabi Zaboors both inspired conversions and enriched spiritual devotion among the converted. In the East African Revival, Tukutendereza Yesu (‘We praise you Jesus’) did the same. Hymn singing and other forms of musical participation often transcended cultural, racial, age, and class barriers. Music united and inspired participants, giving them a shared voice in expressing the transforming power of the Christian gospel. In the global evangelistic ministry of Billy Graham, countless people responded to his invitation to ‘come forward and receive Jesus’ in the context of the hymn, ‘Just as I Am’ (lyrics by Charlotte Elliott, 1835).

5.12 Converting

For those who reflect on Christian experience, conversion is not a singular or static event, but an ongoing process. The Puritan Thomas Shepard’s advice to his congregation, ‘be always converting, and be always converted’, epitomizes this dynamic in the history of Christian conversion (Shepard 1971: 632). Initial conversion may begin with or culminate in baptism, but in either case, baptism is one stage in a conversion process that is never complete in this life. Christian conversion is more properly understood as a continuum than as a punctiliar event. Some converts remain at an initial stage (e.g. one of nominal belief and participation), whereas others progress to a deeper commitment. Catholic writers since the medieval period emphasized a two-fold progression from a ‘first conversion’ at baptism to a ‘second conversion’ in actualizing what the Christian has already received. A ‘first’ conversion may be a dramatic experience or a moment of crisis, followed by repeated turnings or other moments of crisis. In other cases, the first conversion may be imperceptible; then subsequent discernible moments follow.

5.13 Coercion

Depending on the circumstances, coercion may be used to encourage Christian conversion, or it may be used to deter conversion. In both cases, coercion occurs on all levels – national, regional, local, and familial; in varying degrees – from merely acceding to a leader’s wishes to intimidation to threats of violence to incarceration to death; and by various means – the separation of families, physical dislocation, loss of social standing, and economic ruin. Coercion as a tool of conversion abounds in the medieval and early modern periods. Charlemagne forcibly converted pagan Saxons. The Sword Brothers waged crusades in the Baltic region, giving pagans the ultimatum of surrender and receive baptism or die. Throughout the medieval period, local leaders and powerful rulers colluded with Catholic mobs and clergy in forcing Jews to convert. From the beginning of conquest in Latin America, royal officials required that the Indigenous population pledge obedience to the Catholic monarchs and convert to Christianity, and religious orders used coercive tactics in bringing Native peoples the faith. In Peru, Catholic authorities waged a full-scale extirpation of idolatry campaign against the Andeans. In early modern Europe, as confessional boundaries tightened, Catholics and Protestants exerted increasing pressure and resorted to violence to convert the other group to their brand of Christianity. As Western conquest and colonization expanded globally, so too at times did missionaries violate the integrity of indigenous cultures by their cultural imperialism. At the same time, coercive tactics have been used to dissuade people from converting to Christianity. The sporadic persecutions of Christians in the first three centuries, Mao’s Cultural Revolution, and outbursts against low-caste Christian communities in India attest to conscious efforts to quell conversion to Christianity. Just as there have been convert wars, so there have been wars on converts.

5.14 Communication

Without communication, there is no conversion. Some form of divine communication may confirm the reality of conversion, but conventional human forms of communication typically precede divine awareness. Throughout the history of Christian conversion, the primary means of communication has been the spoken word – preaching, testimony, dialogue, debate, conversation, catechism, and song – be it in person, or, more recently, radio, television, recordings, tapes, the internet, and other audio-visual or social media. Not far behind in literate cultures is the written word: the vernacular Bible, devotional literature, tracts, and spiritual autobiographies. The introduction of Christianity in China, India, and Africa were often coterminous with print; in some cases, Christianity became inseparable from religious texts. The spoken and written word often coalesce in educational outreach, another critical means of conversion.

In some places, the physical landscape becomes a converting landscape: Christians have destroyed pagan temples, shrines, altars, and spatial arrangements and Christianized them. They have planted crosses, erected Christian burial sites, and built Christian holy places (sometimes over pagan sites), all the while displacing remnants of paganism. Actions have also proved decisive: demonstrations of God’s power over nature, gods, demons, and ancestral spirits through miraculous healings, exorcisms, and other interventions. The visual has also been put to strategic use through dramatizations, processions, rituals, and other visual props. For some, communicating for conversion is big business; the Great Commission (Matt 28:19) is a multibillion-dollar enterprise.

5.15 Recent scientific perspectives

Empirical investigations of the determinants of religious conversion have been extensive. Beginning with the work of Edwin Starbuck (1897; 1899), who linked conversion to stages of human development (particularly at the youth stage), sociologists, anthropologists, psychologists, and economists have theorized, quantified, and conducted surveys to explain the nature of, and reasons for, conversion. (For a succinct review of these studies, see Barro, Hwang, and McCleary 2010: 16).

More recently, neurotheology – a diverse and multidisciplinary field of study – seeks to assess changes in brain activity with specific religious practices and mystical states (that may include conversion). In his now classic Varieties of Religious Experience (1902), William James, the psychologist-turned-philosopher, hypothesized that ‘[a]ll states of mind are neurally conditioned’ (James 1902: xxvii, 14) – an insight that brain scan studies now confirm (Newberg and Waldman 2016: 40). Recent breakthroughs in cognitive neuroscience, neurology, and psychology have resulted in fruitful efforts to measure subjective religious experiences. Well over one hundred neuroimaging and physiological studies have been performed on people engaged in religious or spiritual practices (e.g. meditation, prayer, speaking in tongues), demonstrating changes to brain activity during such practices (Newberg 2018: 197).

Unlike religious and spiritual practices, measuring the brain activity in a sudden religious conversion is impossible, for the experience itself cannot be reproduced in a laboratory setting. A convert may recount the experience but can never recapture the moment. However, scholars extrapolating the results from surveys and questionnaires focusing on spiritual experiences have correlated the consequences of spiritual enlightenment (which may include conversion) – such as a transformation of belief and behaviours, altered relationships, a sense of surrender or loss, a sense of clarity and new understanding – with brain scan studies indicating changes in neurological activity (Newberg and Waldman 2016: 48–65). Moreover, when people relive the feeling of enlightenment (or in a Christian context, testify to conversion), it reinforces not only the elements of change to the testifier but also to those who witness the testimony.