1.3.1 History

The term ‘secularization’ denotes a process by which (gradually or rapidly, unintendedly or intentionally) the ‘religious’ gives way to the ‘secular’. Its origins lie in various church–state conflicts, such as Henry VIII’s (1491–1547) expropriation of monasteries and other church possessions, moving them from the ‘sacred’ domain of the Church to the ‘worldly’ domain of the Crown (Dobbelaere 2002: 22). Various governments have followed suit, such as France in the late eighteenth century and Germany in the early nineteenth century. An interesting example is the Secularization Act in Mexico (1833) by which the government nationalized the Spanish missions, transferring their ownership from the Franciscan Order to the Mexican state.

As of the early twentieth century, the term was used more generically to describe the process of nations, institutions, and persons becoming less ‘religious’. As such, ‘secularization’ assumed the characteristics of a ‘grand narrative’. For the first generation of social scientists and for many theologians alike, it was a catch-all term. Secularization was a narrative that was told about ‘modernity’, a modernity where religion was irrevocably losing its significance (Hunter 2015; cf. Gorski 2000). This narrative had a great influence among the cultural elites until the 1960s, leading to both pessimistic and optimistic perspectives of secularization, and justifying rather contradictory policies (see section 2.2). In the 1970s, however, the sociology of religion took a more professional turn, focusing on statistical analysis of correlations between several parameters of ‘modernity’ (say, industrialization, urbanization, individualization) on the one hand and religious parameters (e.g. churchgoing, belief, praying) on the other (Stolz 2020; cf. Bruce 2011). While this produced more evidence-based theories, secularization became less of a comprehensive ‘theory of modernity’. Rather, secularization theory fragmented in different, sometimes contradictory theories; it became a ‘hotchpotch of theories’ (Hadden 1987: 588).

1.3.2 Secularization as predicated on Christianity

The term ‘secularization’ predicates on the possibility to define both the ‘secular’ and the ‘religious’, and subsequently to distinguish them from each other. As explained above, this distinction ‘emerged as a theological category of Western Christendom that has no equivalent in other religious traditions or even in Eastern Christianity’ (Casanova 2011: 56). It is therefore suggested that to raise the question whether ‘secularization’ happens in the Majority World is to project a historically Western and Christian dichotomy between ‘sacred’ and ‘secular’ on societies where this dichotomy may not be as relevant or even understood at all. On the other hand, this raises an interesting question. If concepts like the ‘secular’ are indeed so deeply rooted in a Christian worldview, we may ask to what extent Christian mission is instrumental in spreading the conditions under which secularization of a more Western type may happen in the Majority World as well (see section 2.3.1).

Here, too, theologians should be careful to explain what they mean when they talk about ‘secularization’. Even when theologians use different terminology, it is important to be conversant with attempts to define and categorize ‘secularization’ in the social sciences. For example, the term ‘post-Christendom’ that is often used in missiological literature may resonate with the social science term ‘differentiation’ (explained below), especially the separation of church and state. Exploring such resonances may help missiologists to be clearer about their use of ‘post-Christendom’ and the implications they draw from it.

1.3.3 Dimensions of secularization

In social theory, ‘secularization’ is approached as a multi-layered phenomenon. At least five definitions of ‘secularization’ are utilized: differentiation, rationalization, privatization, pluralization, and decline of religion (Paas 2011).

1. Differentiation. This denotes the process by which various social institutions (like education, health care, science, art) are becoming independent from religion (Dobbelaere 2002: 29). Their definitions, aims, and legitimations are increasingly articulated without reference to religious sources or aspirations. The prime example of this is the separation of church and state. For religion, this means that it becomes an institution among others. In other words, through societal differentiation, Christian religion is increasingly identified with its institutional expression, the church. For social scientists, differentiation is the least contested dimension of secularization theory. Virtually everybody agrees that all modern societies are ‘secular’ in this sense (Furseth and Repstad 2007: 97–107).
2. Rationalization. Because of differentiation, institutions have developed their own ideologies and justifications, leaning on reason and science, separate from religious norms (Luckmann 1967: 101). Thus, the realm of the ‘secular’, that is, the domain within the reach of human understanding and control, have expanded. The world lost much of its ‘magic’. Sometimes, this process is called ‘disenchantment’, a term coined by the German sociologist Max Weber (1864–1920). Churches, too, had to abide by this new structure of society; they had to become institutions with their own rational and pragmatic ideologies. For example, churches had to think about planning for mission or about professionalizing their clergy (Dobbelaere 2002: 35).
3. Privatization. Due to the loss of religious influence in the public sphere (because of differentiation and rationalization), religion’s primary focus shifts to the ‘private’ life of subjective spirituality, the family, and congregations. For decisions in politics or business it becomes largely irrelevant whether one believes in God or not, and therefore religions withdraw (or are pushed back) from the public sphere (Luhmann 1982). As we have seen above, part of this is descriptive (a consequence of historical forces), another part of it may be ideological (a consequence of aggressive secularism). As far as description goes, privatization has been contested as a structural feature of modernity. It may even be the case that in late modern societies, where religion plays less of a role in the individual lives of most citizens, religious symbols and narratives have become more prominent in public life – partly because of culture wars (Casanova 1994: 215; cf. Cremer 2023).
4. Pluralization. When the ancient sacral union between church, state, and society collapses, spaces are opened for new religious ‘suppliers’. Secular societies, in this view, are societies where religious monopolies no longer hold. Consequently, such societies become more pluralistic. This creates ‘religious markets’ where minority movements see an opportunity to present themselves – for example, through vigorous ‘church planting movements’ in European nations or in the post-communist world (Paas 2016). Also, religious plurality is caused by immigration of religious people, both from Christianity and other religions. In a secular society they usually have equal rights (at least, formally), since citizenship no longer depends on belonging to the ‘right’ church, or any church at all.
5. Decline. While the previous four dimensions are all part of serious secularization theories, ‘secularization’ in popular speech is mostly associated with the decline of religious beliefs and practices. On this level, secularization means that people find their religion not as important as they used to, their religious beliefs become less orthodox, or they disappear, and (in historically Christian societies) they stop going to church or having Christian burials.

1.3.4 Drivers of secularization

As for why secularization happens, social scientists have suggested multiple drivers, some overlapping with causes mentioned by theologians since times immemorial (Martin 1978). Government policy (laicization) plays a role, historically in countries like France, Russia, China, and South Africa (Vorster 2013), but possibly also today in the context of development aid where, according to some observers, a secularist approach of social justice is imposed on religious societies (cf. Kurfi 2013). Rationalization is a classic explanation of secularization, mentioned already in the nineteenth century by the founding fathers of sociology (cf. Furseth and Repstad 2007: 29–48). By rationalization, it is increasingly possible (or so it is argued) to explain the world and to find foundations for morality and politics without taking recourse to religion. Often, rationalization is fostered by (higher) education, where scientific approaches of the world are substituted for religious explanations. Generally, this means that more highly educated echelons of a population are more secularized than others (e.g. in South Africa; Vorster 2013). Changes in family life due to economic and demographic developments are an important driver too (Tanye 2010; Kimathi 2017). Often, increasing religious pluralization is mentioned as an important factor as well. The multiplication of options and the realization of being surrounded by people who are just as smart and moral as yourself, while they have very different beliefs, tends to undermine strong religious beliefs (Berger 1967; Taylor 2007). Yet another driver, resonating with much of what is already found in the New Testament and in the Christian tradition, is wealth – or, rather, existential security (Norris and Inglehart 2011: 243–252). Finally, on a personal level, disappointment or frustration with religion may play a role in the erosion of a religious approach of life. Think, for example, of the reported rise of agnosticism and atheism in Rwanda after the genocide of 1994 (Beloff 2015).

Factors like these may help to explain why societies have less room for religion, why people lose their faith or why they invest less energy in educating their children into their religion. In more recent theories of secularization, this failing social transmission is a key tool in explaining why secularization in the West seems to follow a generational rather than an individual pattern. That is, while relatively few people lose the faith they had as young adults, far more are unsuccessful at (or lack the motivation for) transmitting their faith to their children (Crockett and Voas 2006). This leads to every new generation being less religious than the previous one. Building on this insight, social scientists have developed a stadial approach in which this pattern of secularization is modelled on a world scale. Secularization, according to this model, is happening in three stages. The first stage begins when participation in religious rituals starts to decline. In the second stage people tend to find their religious beliefs less important than previous generations. And the third stage is inaugurated when people shed their religious affiliations altogether (Stolz et al. 2025).

For missiologists and other theologians, it may be an important insight from the social sciences that secularization usually does not begin with doctrinal insecurity or religious doubt, but with a decrease in participation. Apparently, the process of secularization predicates on changes in lifestyles, often caused by political, economic, and demographic transitions. To the extent that they are aware of this, missionary practitioners are usually interested in the transformation of societies and (public) morality, alongside the saving of souls (see section 2.1.1).

2.1.1 Engaging with the secular

Inevitably, Christian mission deals with the ‘secular’ realm, that is, the world of food, sex, dress codes, work, money, politics, health, and everyday life. Even if Christian missionaries have generally tried to distinguish between the ‘temporal’ and the ‘eternal’, or between ‘natural’ and ‘supernatural’ benefits of the gospel, there is the simple fact that for most people in this world their religion is bound up with war, fertility, prosperity, and health. That was the case in the Roman Empire, and it has been the case ever since. Abundant are the accounts of Christian missionaries who replied to the questions of ‘heathens’, arguing that the Christian God was stronger, promised more success, and represented a political realm that was vastly superior to that of the Franks, Anglo-Saxons, or Frisians in early Europe, or to that of the Ewe, Yoruba, Tshwane, or Zulu in African missions in the nineteenth and early twentieth centuries (Fletcher 1997). Surely, people can only understand the gospel from the place where they are, and with the intellectual and moral categories they have. From this position and within these categories they try to understand how the Christian gospel is good news for them.

Missionaries could be uncomfortable with these ‘worldly’ reasons people had for accepting Christianity. Birgit Meyer, in her study of the Ewe from Ghana, and John D. Peel, in his study of the Yoruba from Nigeria, both describe how nineteenth-century European Protestant missionaries were disappointed about the ‘exteriority’ of conversions among these West African peoples. Very few converts met the evangelical Protestant criteria of a profound understanding of sins, inner experience of forgiveness through the blood of Christ, and a radical conversion to a life of discipline and morality according to European standards. People converted to Christianity because they looked for ‘power’ (alafia):

Personal protection from enemies seen and unseen, healing and fertility, practical guidance through the uncertainties of life, all summed up in that state of worldly well-being called Alafia – these were the fruits of power which Yoruba most looked for from Christianity, as from all other cults. (Peel 2000: 219)

Reports from the Ewe were no different. They converted, for example, because of the medical care missionaries could provide; or because of their disappointment that the gods hadn’t healed their child; converts saw an opportunity to improve their marginal position in society; they liked the cheaper funeral rites of Christians and the fact that Christians seemed to be less afraid of the spirits of the deceased, and so on (Meyer 1999: 11). Their conversions were serious, but their motivations often did not align with the hopes of the missionaries. They experienced redemption but not necessarily from a conscience burdened by sin. The constant maintenance of communities, with all the belonging rituals, sacrifices, incantations, and rigid lifestyles or hierarchies, could be suffocating and frightening. Christianity offered them liberation and a new way of life in a world of beginning globalization (Meyer 1999: 12–14, 90–99).

Examples like this one further illustrate the risk of projecting Western categories of ‘secular/religious’ on the Majority World. For example, Benno van den Toren suggests that there is a specific form of ‘secularization’ in Africa, namely ‘the secularisation of religion by making religious practices […] serve secular goals’ (Van den Toren 2003: 11–12; see Theology in Africa). To this he adds a concern about the ‘charismatic movement’ in Africa, which combines ‘a health and wealth Gospel with a theology that sees financial and physical prosperity as a direct consequence of a life according to God’s will’ (Van den Toren 2003: 26). From a Christian perspective, says Van den Toren, ‘the God-directed focus should be a central element of true religion in distinction from all sorts of semi- or even pseudo-religious practices’ (Van den Toren 2015: 109). Theologically, this may be correct, especially when faith in God is made entirely dependent on God’s perceived ability to provide income, health, or success in business. God is, after all, not a machine or an idol who can be persuaded by the right formulas and rituals. Yet, from a social science perspective, this observation may be predicated on the possibility of a clear conceptual distinction between the realms of the ‘religious’ and the ‘secular’, a distinction that is less clear (or absent) in cultures with a different history from Western Europe. After all, if anything, the fact that people expect God to give health and wealth and other earthly goods is hardly evidence of secularization. On the contrary, it suggests a belief that God is real and active, and that he responds to prayers. If Africans would stop praying for health and money, and turn to other means to achieve these goals, this would be a sure sign of their secularization.

In short, it is a category mistake to confuse the ‘secular’ dimension that every religion inevitably has (and which, in fact, points to the importance of religion in daily life rather than its opposite) with the process of secularization by which religion loses its importance and is relegated to abstract, non-consequential spheres (Paas 2019: 39–40). At the same time, this observation points to the fact that for theological reasons Christian missionaries have often contributed to the secularization of the mindsets and societies of their hosts, in their suspicion of all too ‘magic’ or ‘superstitious’ approaches of God (see section 2.2.2). In a strange way, they could find their host societies too religious rather than too secular.

2.1.2 Transforming the secular

Christianity’s engagement with the ‘secular’ is necessary too, because faith in God has consequences for everyday life. The Bible testifies to this on almost every page, beginning with the Torah (the first five books of the Hebrew Bible). In the New Testament, Jesus gave the Sermon on the Mount with a long series of rules for life. The apostles debated among each other whether circumcision was still a requirement for Christians. Food was a hot topic as well, as in almost every culture. The Apostle Paul’s churches wanted to know whether Christians are allowed to eat food that is dedicated to idols. And may Christians divorce their spouses? What about money? How should they deal with power? What does a Christian community look like?

In all sorts of ways, the ‘secular’ thus presents questions to the ‘religious’. New converts in early Europe asked missionary monks whether it was allowed to have sex on Sundays, or if one could marry their second cousin. Kings asked about waging war, and if they didn’t ask, bishops were eager enough to correct or reprimand them when they indulged in excessive violence. Should Christians bury their deceased children? Can one eat beef, and on which days? Is it allowed for Christian slaves to join their ‘masters’ in attending a temple? Do Christian priests have any rituals in supply for obtaining a good harvest? How do Christians marry? Typically, missionaries have approached such questions through the lens of ‘sanctification’ (Irving-Stonebraker 2019), that is, how the gospel shapes our individual and communal lives under the guidance of the Holy Spirit.

Through this process of sanctification, Christianity produces Christian persons, Christian (sub)cultures, and Christian history. It is a ‘world-formative’ religion (Wolterstorff 1983). Christianity creates art, buildings, rituals, identities, worldviews, communities, traditions, and politics. This is a never-ending process, because christianization is never really ‘finished’, and every time poses its own questions and challenges. Moreover, with the sociologist David Martin one can observe ‘a dialectic of faith and nature’ in the history of Christian culture formation (Martin 2005: 3–7). To the extent that Christianity is successful in its sanctification of the secular, two things are inevitably happening. First, Christianity assumes features of that what is ‘sanctified’, just like flour and yeast are mixed to make bread. If one creates Christian politics, it is not just politics that is christianized. Christianity itself too assumes ‘worldly’ traits of power play, hierarchy, and nationalism. The same goes for building ‘Christian families’. Our ways of living in relationships of blood and kin may become more ‘Christian’ in some ways, but simultaneously Christianity assumes ‘familial values’ to the extent of becoming middle class and bourgeois. Second, every successful ‘sanctification’ of the secular tends to ‘naturalize’ again, or so Martin argues. That is, a few generations later people tend to forget the Christian roots of what has become daily routine to them. Western culture may be profoundly impacted by its Christian history, but for most people it simply feels ‘secular’ in the sense of ‘not religious’ or ‘just natural’. And this is so, precisely because Christian mission has been so immensely successful in shaping the mindsets and lives of modern citizens. There is now a whole cottage industry of books to remind secularized Westerners how culturally Christian they are, precisely because of this re-naturalization of what once was felt as Christian innovation (e.g. Holland 2019).

2.1.3 Mission shaped by the secular

In his influential missiological textbook Transforming Mission (1991), the South African missiologist David Bosch has a long section titled ‘Mission in the Wake of the Enlightenment’ (Bosch 2008: 262–348). Here, he describes how modern Protestant missions since the late eighteenth century have adopted many characteristics of early modernity. In a culture of beginning differentiation (see section 1.3.3), various ‘secular’ (pragmatic, scientific, rational) discourses developed to legitimize politics, education, healthcare, colonialism, or economics without (much) reference to religion. Consequently, a wealth of arguments and means became available helping missionaries to further their cause of bringing the gospel to ‘uncivilized’ parts of the world. One could say that the ‘Christian civilization’ of the West took a new shape, that of a largely ‘secular’ approach of mission (and many other things), wedded with a strong emphasis on converted, regenerated individuals in whose hands the tools of mission were supposed to be safe. Increasingly, people began to talk about mission as essentially a human task that can be achieved when the right tools and means are used by the right (regenerated) people.

This new missionary consciousness had its roots in the Evangelical Revival movements of the eighteenth and nineteenth centuries. These movements can be seen as attempts to reconcile a traditional Christian cosmology with the demands of a modern age, when governments no longer felt responsible for the christianization of their subjects (Stanley 2001). Among leading Christian intellectuals, widespread concerns arose about the beginning secularization of European societies. Christian civilization, therefore, had to be rooted in the hearts and minds of ordinary citizens rather than in the good will of princes. The West’s ‘soul’ should be a ‘Christianity of the heart’, that is, a committed core of converted individuals (Walls 2004: 84). As such, Christianity took the modern shape of a democratic movement: converted, activist, frugal, self-confident, and hardworking individuals who through all kinds of organizations and societies embodied a reinvigorated Christian nation and empire. This is why the revivals have been called ‘an Enlightenment of the common man’ (Himmelfarb 2004: 126).

These cultural developments went together with theological innovations. For example, assurance of faith now became a standard possession of all true Christians (Bebbington 1989: 6–7, 46; Hindmarsh 2005: 141). According to the revivalists, absolute assurance of salvation was possible, precisely because our moral achievements are not the reason why God allows us in his heaven. Only Jesus’ sacrifice assures our salvation. Increasingly, this possibility of assurance was bound up with the use of means and methods. For example, the Sunday Schools that became popular in the 1780s aimed to produce conversions with all the pedagogical tools one could muster. In this context, it became normal for young adults to go through a conversion experience (Bebbington 2000: 122). During the nineteenth century, it became routine to set up special conversion meetings or revival camps, and missionary pioneers like Charles Finney (1792–1875) perfected the art of conversion. There was a modern, almost Kantian feel, to all this: conversion was a moral imperative. One should not wait until it happened, but one should actively seek it and proclaim that one trusted the work of Christ. And since God does not ask from us what we cannot do, this means that conversion must be seen as lying within the reach of human capability (Bebbington 2000: 124–125).

From this matrix, a new approach of mission emerged. Increasingly, mission could be seen as a project, a military operation, or a business strategy. Mission adopted measurable outcomes, goal-oriented assessments, skill-based selection of staff; it embraced competition with other organizations, and it used styles of reasoning based on effectiveness. The use of maps and statistics became a routine. At the World Missionary Conference in Edinburgh (1910) the slogan was: ‘The Evangelization of the World in This Generation’. Books were written about strategies and methods to accelerate the number of conversions (e.g. Allen 1912). In short, in a differentiated society, mission became a religious institution drawing from rational, scientific, and pragmatic resources to legitimize and promote its cause – just like other institutions. Moreover, within a colonial context, mission could be reframed as a crucial method of expanding (Western Christian) civilization until the ends of the earth. After all, for building a Christian society one needed converted individuals. Missionaries could provide the spiritual strength needed for wise governing of the colonies, and for defending them against ‘savage tribes’ (Bosch 2008: 305).

Hence, many missions aligned themselves with the expanded sphere of the ‘secular’, and they learned to speak its language. They worked as efficient organizations, mapping the world strategically, doing ‘market research’, and often working closely together with the colonial authorities. In this context, mission could be seen as having a dual purpose of ‘civilization’ and ‘conversion’, or – in a slightly different phrasing – as ‘Christianization, civilization, and commerce’ (cf. Stanley 2001; Kwiyani 2025). Similarly, and especially after the Second World War, American Protestant missionaries went out not just to proclaim Jesus but to spread an ‘American gospel’ of individual conversion, disestablishment, democracy, self-organization, and liberty.

2.1.4 Contraction of the sacred

Particularly in the later stages of the Evangelical Revivals, when Puritan theocratic memories had faded away, revivalist spirituality did not only fan vigorous evangelism but also opened a wider space for the secular. In this sense, ‘enthusiast’ Protestantism went hand in glove with the differentiation of society, that is, the expansion of the ‘secular’. There are two reasons for this.

First, by raising the bar for ‘true’ Christianity to unprecedented heights, the status of the vast majority of Christians became suspect. After all, many did not go through the typical evangelical conversion process, and many others kept their distance from the evangelical ‘enthusiasts’. Revival preachers called them ‘nominal Christians’ or even ‘baptized pagans’ (cf. Paas 2012: 57–58). This tension between the converted few and the unregenerated many is, in fact, a recurring pattern in times of revival, as David Smilde, for example, has shown for Latin America (Smilde 2007: 157–183). However, this also meant that many so-called ‘cultural Christians’ were faced with a choice: either one was a ‘true’ Christian, or a Christian ‘in name’ only. And given the fact that for many the ‘real’ thing was not achievable, it became easier for them to forget about Christianity altogether (cf. Ryrie 2019). In this way, revivalist Christianity may have unintendedly contributed to the secularization of its societies.

Second, in its focus on the saving of souls above everything else, revivalist Christianity tends to disregard many issues that were previously seen as ‘sacred’ or necessary for salvation. Think, for example, of ecclesiology, the offices, confessions, government, or the sacraments. Of course, such topics were not seen as completely unimportant, but their importance was secondary compared to saving individuals from hell. In other words, ‘salvation’ was trimmed down so that conversions became easier to produce, and cooperation between different denominations in the mission field was not hindered by theological niceties. At the same time, this contraction of the sacred opened a wide ‘secular’ space around the individual saved soul, a space where little if anything was relevant for salvation.

A contemporary example of this ‘fierce pragmatism’ (Abraham 1999: 77) may be the Church Growth Movement, which originated in the United States in the middle of the twentieth century. It claims that the purpose of mission is the numerical growth of converts, measured by baptism or a simple statement of faith. By its concentration on achieving the highest number of individual conversions as efficiently as possible, it tends to ignore or downplay other dimensions of Christianity (McGavran 1990: 8–9). Thus, the domain of the ‘religious’ (e.g. the domain pertaining to salvation) shrinks to the utmost minimum, in the interest of rapid and efficient church growth. Consequently, the Church Growth Movement elevates numerical growth as the justification of almost any method or strategy, short of those that are obviously immoral. An example is its ‘homogeneous unit principle’, that is, a mission strategy based on the idea that people do not like to be together in one church with people from a different ethnicity or social class. Therefore, it is recommended to have ‘homogeneous units’ since they tend to grow faster than churches with a variety of people from different backgrounds (McGavran 1990: 198). Thus, a purely quantitative justification is found to separate salvation from ethnic and social reconciliation within the church.

2.2.1 Secularism as a rival

While the World Missionary Conference of Edinburgh in 1910 could still build on a rather unproblematic division of the world into (non-Western) ‘mission fields’ and (Western) ‘mission bases’, its successor in Jerusalem (1928) struck a different note. Crucial in this regard was a paper presented by Rufus Jones, titled ‘Secular Civilization and the Christian Task’. Western Christians, he wrote, face ‘within their own borders the competition of a rival movement as powerful, as dangerous, as insidious as any of the great historic religions’ (Jones 1928: 273). In a reflection on this conference, published a year later, Basil Mathews concluded that in Jerusalem 1928 the Western world had learnt to see itself as a ‘mission field’ (Mathews 1929: 211). Clearly, Jones’ introduction of the ‘secularism’ as Christianity’s ‘rival’ played a great role in this new understanding. The terminology was consciously modelled after the way non-Western religions, like Hinduism or Islam, had been described in the Edinburgh conference of 1910. In other words, Jones suggested that Western Christianity within the borders of its historic heartland had found a formidable adversary, an alternative ‘religion’, as it were.

In the 1930s, the Dutch missiologist Hendrik Kraemer published his famous The Christian Message in a Non-Christian World (1938). Here he defined Western ‘relativism’ and ‘secularism’ as rebellious ideologies, forgetful of their Christian origins. Especially the rise of Nazism (‘tribal religion’) was a matter of concern. According to Kraemer, nothing demonstrated more clearly ‘that the Christian Church, religiously speaking, in the West as well as in the East, is standing in a pagan, non-Christian world, and has again to consider the whole world its mission field, not in the rhetorical but in the literal sense of the word’ (Kraemer 1938: 16–17). This relationship of Christianity with what has been termed ‘secular culture’ remained an important part of discussions in missionary conferences.

Meanwhile, opinions differed as to how to value ‘secularism’, or how to understand it in the first place. Even at the Jerusalem conference not everyone agreed (Gill 1968). Was ‘secularism’ a threat or an opportunity? Rufus Jones himself wrote how secularism could represent some of the best ‘deep-lying forces of life operating […] in the world’, and he mentioned science’s ‘honesty, care, methodological accuracy and relative freedom from the barriers of superstition, as well as its contribution to human welfare and betterment’ as an example (Jones 1928: 301, 327). Other participants pointed out how Kemal Atatürk’s (1881–1938) secularization programme had broken Turkey’s bondage to Islam (as they saw it), and in so doing had opened the country for Christian mission (Gill 1968: 349–350). More critical analyses focused on secularism’s perceived ‘materialism’, ‘agnosticism’, and ‘naturalism’. Such views echoed concerns that had been heard within Western Christianity since the late eighteenth century: increasing industrialization and urbanization led to the rise of a new type of ‘man’, only concerned about the mundane, dulled by money and temporal goods, and vulnerable to every ‘political religion’. They feared that secularism’s drive to push the sacred out of the public domain would cause new, ‘secular’ gods to raise their heads and fill the gap that religion left behind.

Behind those critiques of ‘secularism’ lay different theologies. Many liberal Protestants, for example, were appreciative of secularism because they recognized in it the ancient Protestant drive to fight ‘superstition’ and ‘priesthood’, and they liked its advocacy of ‘liberty’ and ‘reason’. However, some of them lamented the falling apart of ‘Christianity’ and (Western) ‘civilization’, especially over against purportedly ‘aggressive’ secularist attempts to ban religion from the public life (Edwards 2015). Their opponents, inspired by Karl Barth (1886–1968), did not share the liberals’ attachment to cultural Christianity. In fact, they warned against liberal attempts to ‘modernize’ Christianity to make it fit for a new marriage between Christianity and modern culture. However, their polemical instincts were aroused by forms of secularism that dressed themselves as new religions, particularly Marxism and Nazism. And for many conservative Christians, Catholic and Protestant alike, secularism was a threat because of its hostility against the public, ‘world-formative’ dimension of Christianity. For them, despite all its faults, Christendom had been a missionary ideal, an outworking of sanctification in society and politics. Pope Leo XIII expressed this sentiment in his encyclical Immortale Dei (1885), where he wrote, rather nostalgic, about ‘a time when States were governed by the philosophy of the Gospel […] and divine virtue of Christian wisdom had diffused itself throughout the laws, institutions, and morals of the people’ (section 21). The Dutch Reformed theologian Abraham Kuyper had articulated a similar feeling, a few years earlier (1880): ‘There is not a square inch in the whole domain of our human existence over which Christ does not cry “Mine!”’ (Kuyper 1998: 488).

While the appreciative stream got the upper hand among liberal Protestants in the 1960s (see below), anti-secularism was revived by Catholic writers after the Second World War (e.g. Dawson 1956; Weigel 2005). Their critique of secularism was also inspired by Catholic programmes of ‘re-evangelization’ (Dulles 1988: 144–149; cf. John Paul II 2003), with a strong emphasis on reclaiming the public domain for Christianity, and on cultural evangelization (art, science, education). Typically, anti-secularist language flares up around controversial issues like religious schools, religious symbols in court rooms or in other public buildings, or legalizing same-sex weddings (for an example, see Ellul 2015). Similarly, conservative Protestants have taken up the anti-secularist baton after the 1970s. While their critique was originally aimed at mainstream Protestants who, in their view, leaned in far too much to ‘secularist’ values like relativism, the separation of church and state, and the equality of all religions, more recently their polemic has morphed into assertive culture wars (especially in the United States) about the future of a ‘Christian nation’ threatened by immigration, gender equality, and liberal, left-leaning politics (Kobes du Mez 2020; Gorski and Perry 2022). Here too, however, just as it is important to distinguish between different forms of secularism, not every Protestant anti-secularist discourse should be framed as a prelude to aggressive authoritarianism. For example, the British missiologist Lesslie Newbigin (1909–1998) wrote a valuable epistemological critique of secularist attempts to separate the (public and objective) domain of ‘facts’ from the (private and subjective) domain of ‘values’ (Newbigin 1989). While his plea for the gospel as ‘public truth’ leaves much to be desired in terms of clarity, his critique of the alleged ‘neutrality’ of secularist positions is crucial in increasingly pluralist societies. Unchecked, secularism in its more polemical and comprehensive forms can assume all the dominating features of the religious monopolies of the past.

2.2.2 Secularism as a guiding ideal for Christian mission

While Catholics and conservative Protestants maintained a largely anti-secularist stance after the Second World War, liberal Protestants changed gear. That is, the positive evaluations of secularism that had always been part of their tradition became dominant to the extent that ‘secularization’ was lauded as the desired and necessary outcome of Christian mission. Even though leading liberal Protestants wanted to distinguish their positive assessment of ‘secularization’ from the supposedly aggressive anti-religious stance of ‘secularism’ (Wickham 1966; cf. Paul 2014), their theology of Christian mission was a ‘secularist’ one in the sense that mission in their view should lead to a liberation of human ‘autonomy’ from oppressive religious authorities and dogmas.

Building on Dietrich Bonhoeffer’s ideas of a ‘religionless society’ and humanity ‘come of age’, theologians in the 1960s argued that modern humans should live as if there were no God. Only when humans refuse the infantile urge to use God as a substitute for science, or as a moral prop for society, can they be free to be truly human. People shouldn’t feel compelled to believe in God as a ‘gap-filler’ to make up for their lack of understanding or moral courage. Hence, Christian mission aims at ‘secularizing’ the world to release the great potential that God has laid in human beings and to allow for a genuinely free and mature relationship between humanity and God (Munby 1963; Van Leeuwen 1964).

According to the American theologian Harvey Cox, in his famous book The Secular City (1965), the modern large city (‘technopolis’) is the most visible expression of humanity’s ‘coming of age’. Since secularization is ‘dangerous’ (liberty comes with responsibility), we must resist any attempts to restore human dependency on supernatural powers or religious institutions. Cox rejects theological criticisms of the city as being too dependent on rural, conservative views of human community, and he presents a theological defence of the city’s characteristics. Cox notes strong parallels between the biblical views of the Kingdom of God and the secular city as its most visible representative. The role of the church is to be a transformative and kenotic (self-emptying) community, a vanguard of the future, focused on witnessing to kerygma (proclamation), diakonia (service), and koinonia (community) wherever they are visible in the secular city. As such, the church should aim at ‘exorcising’ any nostalgic desire of becoming dependent and infantile again. It should not be focused on itself, but on discerning where ‘it happens’, that is, where God is at work in the city (Cox 2013).

With this last reference, Cox echoes the Dutch missiologist Johannes Christiaan Hoekendijk (1912–1975), who was one of the most influential mainstream Protestant voices in mission debates in the 1960s. For Hoekendijk, the antidote to missionary Christianity’s traditional obsession with territorial expansion (often in a colonial framework) was a radical commitment to the missio Dei (mission of God). Hoekendijk recategorized mission as historical rather than geographical. Mission is about being attuned to the eschatological reign of God that draws the world towards his future shalom (all-encompassing peace and wellbeing; Flett 2016: 202–210). ‘Church’ is what happens in this encounter of the kingdom and the world; it is therefore in constant transition towards the end of time. Or, in Hoekendijk’s famous words: the church is ‘a function of the Apostolate, that is, an instrument of God’s redemptive action in this world’ (Hoekendijk 1950: 170). Because of this instrumentalization, the church does not have a separate or unique place. Its mission is not to invite people in or to influence secular communities with gospel values. As a ‘function’ of the apostolate the church can only identify struggles for shalom in this world and join them. It is not to be focused on itself and its own future, but it must turn itself ‘inside out’ – thus a famous book title of Hoekendijk’s (1967). So and only so can it serve the mission of God’s shalom in the world.

The World Council of Churches conferences in Mexico City (1963) and Uppsala (1968) were especially, and deeply, influenced by these ideas. As an instrument of God’s mission, the church should follow the signs of liberation and emancipation wherever they appear in the world. The church should listen ‘to what modern man is saying’ (World Council of Churches 1968). Altogether, the documents from these conferences are infused with a strong optimism about secularization as the coming of age of humankind thanks to centuries of Christian mission. This optimism was one of the triggers behind the emergence of conservative Protestant resistance against secularism in the 1970s (see section 2.2.1), leading among other things to the establishment of the Lausanne Movement (1974).

In his introduction to a later edition of his The Secular City (2013), Harvey Cox presents some important qualifications of his earlier views. First, he admits that he was too attached to a ‘stadial’ view of secularization, that is, in 1965 he saw secularization as the inevitable outcome of Christian civilization. Second, he admits that he has underestimated the dimension of power in secularization. In 1965 he saw secularization largely as a neutral development, while he would now put more emphasis on the (secularist) agendas behind the process of secularization. Here he mentions especially the power of markets and economy, which through secularization have drained the market from ethical dimensions. Third, he would now be more careful to distinguish different types of secularization, especially in a postcolonial perspective. Altogether, Cox specifies his project as a search for a Christian theology of secularization, a work that is still unfinished. Secularization has opened a space where different worldviews will have to engage each other in order to build a ‘good city’. Each worldview, including the secular worldview(s), should contribute to this good city in (critical) dialogue with other worldviews (cf. Jansen 2022: 503–504).

2.3.1 Christian mission as an agent of secularization

The relationship between conversion and Western civilization was a topic of heated debate in the nineteenth century. While all parties agreed that conversion and civilization were two sides of the same coin, there was disagreement about the right order of these two dimensions of mission (Stanley 2001). Most revivalist evangelicals held that a christianized society would emanate from regenerated individuals, whereas many other Protestants believed that people could only convert to Christianity when certain cultural conditions were met first, such as literacy and some moral groundwork. However, in missionary practice these two dimensions are difficult to keep apart, even if they can be distinguished theoretically. After all, one can prioritize ‘conversion’ over ‘civilization’, but inevitably one will define this conversion through the lens of one’s own cultural experience. Hence, Christian mission could easily assume the character of a ‘civilizing mission’, reproducing the missionary’s own idealized conversion biography as the template that would lead the ‘heathen’ to salvation (Comaroff and Comaroff 1991: 59). The Evangelical Revivals, the spiritual matrix out of which much modern Protestant missions have emerged, brought assuredness, both on the spiritual and the societal level. As a disciplining force, evangelicalism was ‘an avenue of upward social mobility’, and thus there was ‘a natural tendency for converted characters to gain skills, find regular employment and so rise out of the lowest ranks of society’ (Bebbington 1989: 25–27, 126–127). In the modern missionary movement that arose from these experiences, this evangelical ethos was considered as the soul of a transformed society, which resulted in promoting the revivalist experience as a key to changing societies haunted by paganism and superstition. Already in 1811, the American Board of Commissioners for Foreign Missions declared: ‘Now is the time for the followers of Christ to come forward boldly and engage earnestly in the great work of enlightening and reforming mankind’ (quoted in Elshakry 2007: 174). In her analysis of American Protestant mission activity in nineteenth-century Syria and Lebanon, Marwa Elshakry shows how ‘enlightenment’ was seen as a precondition for ‘reformation’. Thus, for many missionaries, a ‘conversion to modernities’ (Van der Veer 1995) was a crucial step in the process of preparing ‘backward’ societies for Christianity. Evangelistic mission usually went together with the promotion of Western medicine and science education, with the explicit purpose of demonstrating the futility of traditional ways of thinking and to replace them with a Christian mindset. In the end, this could mean that ‘an exclusively religious concern with conversion was complicated by a growing commitment to secular and civilizing ventures’ (Elshakry 2007: 174).

It is no surprise, then, that Christian mission has been portrayed as an ‘agent of secularization’ (Miller 1970). Even though this claim has been contested in recent research (Kruithof 2021), there is some reason to assume that mission, especially Protestant mission, has contributed to some forms of secularization (cf. Dopamu 2006; Ngarsouledé 2015). Part of this has to do with the fact that much Protestant mission is done by so-called ‘free churches’ (Baptists, Methodists, or Pentecostals) that traditionally stress individual religious liberty as a precondition for true belief. Only when someone’s religion is chosen, it is true. In the words of the eighteenth-century American Baptist Isaac Backus (1724–1806): ‘Nothing can be true religion but a voluntary obedience unto God’s revealed will, of which each rational soul has an actual right to judge for itself’ (Leonard 2005: 15). Similarly, and much later, the Lausanne Covenant (1974) expresses the strong conviction of most evangelicals in this regard:

It is the God-appointed duty of every government to secure conditions of peace, justice and liberty in which the Church may obey God, serve the Lord Jesus Christ, and preach the gospel without interference. We therefore pray for the leaders of nations and call upon them to guarantee freedom of thought and conscience, and freedom to practise and propagate religion in accordance with the will of God and as set forth in The Universal Declaration of Human Rights. (Lausanne Movement 1974: section 13)

The mentioning of the Universal Declaration of Human Rights, a secular document, is significant here. Religious liberty on this view is essentially an individual right, guaranteed by international law.

This pushing for separation of church and state, disestablishment, and religious pluralism has led to tensions between Protestant missions and their host countries, for example in post-communist Eastern Europe, where the Orthodox Churches defend their ‘canonical territories’ against what they see as ‘sects’. But to the extent that such missions are successful, they can contribute to the secularization of their host societies. An example may be Japan, where Protestant missionaries (especially from the United States) have advocated democracy, individual liberty, and economic development, although without reaching the effect they hoped for, namely mass conversions. By and large, the Japanese embraced modernity but they rejected missionary Christianity (Rayl 1996).

Another potentially secularizing influence from Christian mission may be Christianity’s contribution to existential security, through disenchantment on the one hand and increasing confidence in one’s powers of moral ordering on the other. Charles Taylor calls this ‘the buffered self’, contrasting it with the ‘porous self’ that is identified by the lack of a clear boundary between mind and world, thus opening the mind to all sorts of visible and invisible influences from the outside world (Taylor 2007: 27–43). For example, in her study of Pentecostal churches in Mozambique, Linda van de Kamp argues that Pentecostalism’s criticism of traditional social order in Africa introduces a new dynamic of individualism which is actually representative of neoliberal globalization itself rather than an attempt to accommodate socioeconomic change by drawing from religious sources. She asserts that Pentecostalism is a ‘practice of pioneering’, connecting well with the pioneer mentality that can be found in urban settings in Africa (Van de Kamp 2011: 50–51). As such, it may not contribute to a more prosperous society throughout but to a society where there are a few ‘winners’ and many ‘losers’. These self-assured, buffered ‘winners’ might very well become the secularizing core of a future (urban) Africa, especially when they join forces with more rationalizing approaches within Pentecostalism to reduce its ‘devil mania’ and ‘exaggerated demonology’ (Nnamani 2015: 343). However, while Pentecostalism’s capacity to liberate people from unchallenged religious authority and collective patterns may eventually lead people to leave the church altogether, there is as yet no indication that this also leads to a disenchanted worldview. The most we can say is that with regard to Africa’s secularization late modern Pentecostalism is an ambiguous force (more discussion in Paas 2019).

2.3.2 Secularization narratives and mission

As related above, before the study of secularization took an empirical turn, secularization has often assumed the character of a ‘grand narrative’. The Dutch historian Herman Paul, building on Ian Hunter’s work, traces this back to the influence of nineteenth-century ‘historicism’ on early twentieth-century views of secularization. Historicism depicts history as a development of ideas through consecutive eras, which follow one another in an irreversible pattern (Paul 2018: 40). When secularization is shaped through an historicist frame, it tends to become a comprehensive theory of ‘modernity’, whereby ‘religion’ is relegated to a past that is irreversibly lost. Moreover, virtually all anecdotes and data relating to religious phenomena are interpreted through the lens of this irresistible historical process of secularization. Paul suggests that this grand narrative of secularization in fact preceded the actual secularization of the masses in the West during the 1960s and 1970s. In other words, the omnipresent belief that we live in a culture that is secularizing may have produced church-leaving to some extent rather than explained it (Paul 2018: 63).

Grand narratives not only become self-fulfilling prophecies, they also give rise to very different responses. Missionary-minded Christians have seen secularization as a wake-up call for churches, urging them to adapt to the times, to wind back some of their more unpalatable teachings, and to organize themselves in more flexible, entrepreneurial ways to be ready for a secular age (e.g. Wickham 1957). Others drew a completely opposite lesson from secularization. They saw in it the triumph of anti-religious ideologies and the spread of consumerist, superficial, this-worldly attitudes. Consequently, the church had to resist the temptation to adapt itself (which would amount to self-secularization) but offer a robust alternative instead. Evidently, ‘secularization’ can mean different things to different people, depending on their theology.

Finally, it should be remembered that even the most sophisticated theory of secularization is not a law of nature. Different from, say, the law of gravity, secularization is related to ‘particular historical and social conditions, which can be countered or utilized by human ingenuity and imagination’ (Martin 2002: 156). Hence, it is ‘irreversible’ only to the extent that human beings appreciate it and want to keep it. Of course, we move on through history, and to some extent it is true that we ‘cannot turn back the clock’. But secularization itself may open unexpected ‘cracks’ through which the transcendent seeps in. For example, people may start wondering about the future of Western civilization, and reconsider Christianity’s place in it. New generations may experience growing dissatisfaction with an all too dominant secularity, just like previous generations experienced with religion. Far from putting an end to mission, secularization offers new opportunities and new questions for Christian mission (cf. Brierley 2023).