1.1 Incarnation

The incarnation of Jesus Christ is the central teaching that defines Christian churches as a community, along with the identification of God as Trinity. In Christian theology, the verb ‘incarnate’ and its nominal form ‘incarnation’ originates in the prologue to the Gospel of John: ‘The Word (Logos) became flesh (sarx egeneto) and dwelt among us’ (1:14). ‘Flesh’ (sarx) is rendered in a verbal form in the Nicene-Constantinopolitan Creed (the Creed of 381), recited every Sunday by many Christians throughout the world in worship: ‘for us he [Jesus Christ] came down from heaven and became incarnate (sarkōthenta) by the Holy Spirit and the virgin Mary, and became man’ (Tanner 1990: 24, translation altered).

As a verb, ‘incarnate’ or ‘to become incarnate’ is an action term. In Christian grammar, the verb implies a particular subject (as conciliar grammar puts it, a hypostasis, or a terminal individual) who once was without flesh. After having ‘become’ incarnate, that is, at the termination of the action, that subject is now incarnate, or flesh. The Gospel of John identifies that subject as the Word (Logos), the Son of the Father (e.g. John 14:17, 23), who is eternally born from the Father’s side before all worlds and ages (John 1:18). The Creed of 381 identifies this Logos as ‘the Lord Jesus Christ’. This name ‘Jesus Christ’ appears in apposition with ‘the only-begotten Son of God’. This semantic point suggests that the two names, the man Jesus and the eternal Son, do not denote two different subjects. Rather they are, as the Creed says, ‘one’ (hena) in reality, not in name only. As Cyril of Alexandria (d. 444) argued, the faith of Nicaea holds that the man Jesus of Nazareth, who walked in the hillside near Galilee, turned to Jerusalem, and died upon a Roman cross, is ‘one and the same’ as the eternal Word of God (Wickham 1983: 9). Put technically, the state affairs produced by the incarnation is that the Logos just is this man from Nazareth. Jesus is the Word incarnate.

1.2 Preexistence

‘Preexistence’ appears in the context of Christology as an implication of the more scriptural term ‘incarnation’, on which it logically depends. It has tended to appear in more recent theology, especially in the modern guild of historical-critical studies on the New Testament. The present author is not aware of any premodern credal document or theological text that uses a Latin term like praeexistere or a similar term in Greek. Recent New Testament scholarship examines semantic arrangements in the New Testament text that suggest, whether directly or indirectly, that Jesus Christ existed ‘before’ (preexisted) his earthly life. Scholars disagree about which texts suggest preexistence, if any, and they differ in how they understand more explicit texts like the Johannine prologue. For example, it is common to argue that the expansion of early Christian imagination over time led John, writing in the 80s or 90s CE, to assert Jesus’ identity as the Logos. If true, that would explain why an earlier text like Mark is much less explicit on Jesus’ divinity. Among contemporary theologians, ‘preexistence’ refers to Jesus’ own existence in the eternal ‘before’ his temporal advent.

This entry will fall into four major parts. First, it will discuss scriptural texts and foundational judgments that underlay the development of credal definitions of faith beginning in the fourth century, starting with the first council of Nicaea (Nicaea I). Second, it will describe the unfolding of the teaching of what Catholic, Orthodox, and some Protestant Christians receive as the seven ecumenical councils. It will argue that the teaching of all seven councils form one coherent body of teaching on the Logos’ preexistence and incarnation, with the decisions of former councils grounding the decisions of the ones that follow as natural developments. Third, it will examine the doctrine of the incarnation as it forms the life of the Christian community along three axes: public worship, salvation of the sinner, and the sacrament of the Eucharist (or, as it is called among Protestants, the Lord’s Supper). Finally, it will explore contemporary Catholic and Protestant perspectives on the incarnation. This article will refer primarily to English translations of the original texts, since these are more widely available for the contemporary reader.

2.1 Old Testament prefigurations

Until recently, few biblical scholars would claim that the Old Testament refers to Jesus Christ’s incarnation. However, due to the ressourcement movement’s efforts to reclaim ancient Christian readings of the Bible in the last century, contemporary Catholic and Protestant theology and biblical scholarship has recovered typological interpretation of the Bible, or the analysis of the complex of patterns repeated across scripture (e.g. Seitz 2001). Most early Christian interpreters took approaches like these to be basic, and partly because of it they saw the incarnation prefigured (or referenced before it happened) in the Old Testament. For example, in the fourth century, all parties involved in the Arian controversy (see section 3.1 below) agreed that the subject who speaks ‘[t]he Lord created me at the beginning of his work’, in Prov 8:22 was not an impersonal divine Wisdom, but Jesus Christ, the only-begotten (monogenēs) Son of the Father (John 3:16; cf. Wis 7:22). What was up for dispute in the fourth century was not whether the Proverbs text referred to Jesus, but how to understand that reference. Arius thought that the temporal indexical ‘at the beginning’ referred to a moment where the Son began to be. According to Arius, because Jesus had a beginning he is the primordial and most excellent creature through whom the Lord made all things (cf. John 1:3; Col 1:16). Athanasius, following the reading of his great Alexandrian forebear Origen, understood ‘at the beginning’ to be an eternal occurrence. As Origen had emphasized, the Son is always being born of the Father (John 1:18), and the key to understanding the verb ‘created’ in Prov 8:22 depends on Wisdom’s ‘birth’ in 8:25.

Early Christian theologians read the Old Testament like this because the New Testament reveals that Jesus is the Old Testament’s primary subject. If Jesus is the Wisdom of God, as the Apostle Paul claims, then Proverbs refers to Jesus when it speaks of divine Wisdom (1 Cor 1:24). If Moses struck the rock and that rock was ‘Christ’, as Paul teaches, then, so the argument goes, we should not be surprised to find other Old Testament texts referring to Jesus (1 Cor 10:4; cf. 2:9–10; 2 Cor 3:12–18). It was a short step for these interpreters to perceive that the eternal Word of God who was both ‘with’ God in the beginning and ‘was God’ just is the same person as divine Wisdom (John 1:1–2). Origen had also seen clear references to the pre-incarnate Jesus in Genesis 1: Jesus is the spoken divine Word through whom all things were created in the beginning (Gen 1:4; cf. Col 1:15–20). Athanasius extended this insight in a soteriological direction: ‘the recreation of the world was accomplished by the same Word who made it in the beginning’ (2008: 50).

The New Testament also presents other strategies of conceiving of Jesus’ identity by rereading the Old Testament. A growing body of New Testament scholarship argues that the Gospels and Pauline letters identify Jesus with yhwh (Bauckham 2008; Hays 2016; Tilling 2015; Rowe 2006; on the theological approach to reading the New Testament historically, see Keck 2005). Some make this argument from a strictly historical approach (Hurtado 2003), others from intertextual analysis (Hays 2016). The consensus is that the New Testament teaches that Jesus Christ is the Lord of Israel, yhwh, and that a ‘high’ Christology in which Jesus Christ preexists the incarnation can be adduced from the earliest New Testament texts.

Much of this scholarship is responding to the argument of James D. G. Dunn that this high Christology is not present in the earliest texts (Dunn 1980). It perceives what some call a ‘christological monotheism’ in the New Testament, or a revision of the inherited monotheism of Jewish scripture and tradition. Some scholars reject the idea that these proofs are dispositive (McGrath 2009). Others modify the terms of the debate by arguing that Jesus shares in some way in yhwh’s identity but is not fully included in that identity (Fletcher-Louis 2015). Another question raised in contemporary study is why the earliest Christians worshipped Jesus. Larry Hurtado’s influential study of this topic argued that the earliest Christians worshipped Jesus in a phenomenally intense way without parallel in the ancient Roman world, and that they upheld an exclusive monotheism in doing so (Hurtado 2003). By contrast, Dunn (2010)has more recently argued that most of the earliest Christians did not worship Jesus.

Richard Bauckham offers a good example of an Old Testament text that the New Testament interprets christologically. According to Bauckham, the New Testament speaks directly about Jesus as included within ‘the divine identity’ by citing Ps 110:1: ‘The Lord says to my lord, “Sit at my right hand until I make your enemies your footstool”’. For example, in the Gospels, Jesus identifies himself as the heir to David’s throne by citing Ps 110:1 (Matt 22:44; Mark 12:36; Luke 20:41–44). As Bauckham observes, the text on its own need not suggest anything more than that yhwh’s messianic ruler judges from a position of high honour. One could argue that it speaks only of the exaltation of the messianic ruler. Yet Bauckham has argued influentially that the text suggests that Jesus is ‘on the divine throne itself, exercising God’s own rule over all things’ (Bauckham 2008: 22 [see note 39 for a list of biblical references]).

2.2 The Gospels, Acts, and Johannine literature

2.3 Pauline letters

Paul provides additional conceptual development of the divine and human identity of Jesus. In the epistle to the Romans, he calls the man Jesus, the Christ, ‘God blessed forever’ (Rom 9:5). This is the same Jesus who is ‘descended from David according to the flesh’ and ‘was declared to be the Son of God with power according to the Spirit of holiness by the resurrection from the dead, Jesus Christ our Lord’ (Rom 1:3–4). In 1 Corinthians, he includes Jesus in God the Father’s own identity as the ‘one’ creator God by reworking the Shema of Deut 6:4–6 (1 Cor 8:6; Bauckham 2008: 26–30). In Galatians, he depicts Jesus as ‘sent’ from God into the world (Gal 4:4). The Pastoral Epistles then depict Jesus as being ‘manifested’ or ‘appearing’, seen from the perspective of those who know him (1 Tim 3:16; 2 Tim 1:11).

Probably the most influential passage of Paul’s for the theology of the incarnation is Phil 2:6–11, which many scholars believe was an ancient Christian hymn that Paul quotes for rhetorical purposes. Jesus, who was ‘in the form of God’, ‘emptied himself’ (ekenosen) by becoming incarnate and dying upon the cross (2:6–9). Paul alludes to the Lord’s glorification in Isa 45:22–23 when he speaks of Jesus’ glorification: ‘at the name of Jesus every knee should bend, in heaven and on earth and under the earth, and every tongue should confess that Jesus Christ is Lord, to the glory of God the Father’ (2:10–11). The Isaianic text refers to the future glorification of the God of Israel over all nations at the eschatological restoration of the world. Paul’s point appears to be that Jesus’ death and resurrection has resulted in this glorification and anticipates the final eschatological renewal of all things already beginning in him.

Philippians 2:6–11 has also been a source of great interpretive dispute: just what is the nature of this ‘emptying’ (kenosis)? Most theologians before the modern period held that it referred to the incarnation: the Son of God has taken flesh to himself, and in so doing he ‘empties’ himself, but without in any way ceasing to be God. In a major stream of modern theology, however, kenosis has come to refer to Jesus’ emptying or retracting of his divine properties and prerogatives (see Forsyth 1909; Thomasius 1845 [see the translated selection in Welch 1965: 31–101], Mackintosh 1912; for the history see McCormack 2015). The legacy of kenotic theology is still being assessed, primarily in theological quarters influenced by Karl Barth (Nimmo and Johnson 2022).

Other important traditionally-Pauline texts emphasize the primacy of Christ over all creation. Jesus is the ‘image’ of the invisible God and the ‘firstborn’ of all created things who has authority over all creation (Col 1:15–20; cf. Eph 1:22–23). In Christ everything was created and he is primary with respect to all of them: ‘all things have been created through him and for him’ (Col 1:16).

2.4 Hebrews and the Catholic epistles

The short introduction to the Epistle to the Hebrews speaks of Jesus as God’s Word. Like Paul, Hebrews speaks of Jesus as creator and the one who has authority over all creation (Heb 1:2). Not only does he reflect the glory of God (cf. John 1:14–16), but he is ‘the exact imprint of God’s very being’ (Heb 1:3). Despite his divinity, Jesus was also made ‘lower than the angels’ (2:9) and, as a human being, was ‘in every respect tested as we are, yet without sin’ (4:15). As God almighty in the flesh, he is exalted as superior above the angels (1:4, 5–6, 13–14). The Father calls his Son, Jesus, ‘God’ (1:8) and ‘Lord’ (1:10).

Jude contains perhaps one of the most bewildering attestations to Jesus’s preexistence in the New Testament: ‘Jesus, who saved a people out of the land of Egypt, afterward destroyed those who did not believe’ (Jude 5). Jesus is depicted here as the primary agent of Israel’s deliverance from Egypt, a clear signification of his preexistence.

3.1 Nicaea I (325) and Constantinople I (381)

Sometime around 320, an Alexandrian presbyter named Arius began preaching that Jesus Christ was God, but only in an attenuated sense; he is, in fact, the greatest creature that God made, through whom God created everything else (on Arius and Arianism see Williams 2002). Alexander, archbishop of Alexandria, condemned Arius’ works at the time. But Arius’ message became popular and spread throughout the empire. The controversy over Arius’ teaching led Constantine to call for a council of bishops to resolve the issue, which was held in Nicaea, the modern Turkish city of Izmir, in the summer of 325. Present at the council was St Athanasius of Alexandria, Alexander’s former assistant, who campaigned against Arius’ teachings.

The synodal definition of faith, the Creed of 325, echoes 1 Cor 8:6 and the Shema (Deut 6:4–6): it professes faith in one God, the Father almighty, the creator, and in one Lord Jesus Christ. Jesus is related to the Father as his ‘only begotten Son’ (gennethenta ek tou patrou monogenē) (Denzinger and Hünermann 2012 [hereafter DH]: section 125). Against Arius, who supposed that all things that are begotten are also created, Nicaea I teaches that the Son is begotten but ‘not made’, or uncreated (DH: section 125). The Creed of Nicaea therefore sets out in the strongest possible terms the uncreated preexistence of the Son, who is ‘of the same substance’ (homoousion) with the Father. It affirms the humanity of this same Son, who descended from heaven and ‘was made flesh’ (sarkothenta).

As standard histories of the fourth century show, the decades after Nicaea (325) leading up to the second ecumenical council, Constantinople I, in 381, were fraught with ongoing controversy. Doctrinal consensus throughout the empire was nonexistent after Nicaea (see especially Ayres 2004: 85–269; for studies of fourth century trinitarian theology see also Anatolios 2011; Behr 2004; Young 2010). The text of the ecumenical creed of Constantinople I, which had imperial backing (known as the Nicene-Constantinopolitan Creed in many contemporary churches), is not based on the text of the Creed of 325 (it may have been in use much earlier than 381; see DH: section 150). Yet it repeats many of the same judgments as the Creed of 325: Jesus is the only begotten son of God who became incarnate ‘for us and for our salvation’ (DH: section 150). The homoousion is reaffirmed unequivocally.

3.2 Ephesus I (431) and Chalcedon (451)

At the end of the fourth century, the terms of conciliar teaching were set in a speculatively limited but determinate manner: Jesus Christ just is the Son of God, who is both eternally begotten from the Father’s essence and ‘by the power of the Holy Spirit was incarnate from the Virgin Mary’ (DH: section 150). The next five councils would address aberrant interpretations of this basic teaching and develop it in response to these threats. Conciliar teaching in the fifth century focused on what it meant for Jesus to be made incarnate, or flesh, and to remain as the one who exists as God from all eternity.

In the late fourth century, a friend of Athanasius, Apollinaris of Laodicea, claimed that Jesus lacked a human noûs, an intellectual soul, the aspect of him that thinks. That part of him was replaced entirely by the divine intellect (Norris 1980: 103–111). Due in part to the theological leadership of Gregory of Nazianzus, the Council of Constantinople I ruled that Apollinaris’ teaching be condemned (canon 1, DH: section 151). As Gregory argued, Apollinaris undermined the reality of the incarnation, for if the Son did not take on a human intellect then he did not heal the nature he assumed (Gregory of Nazianzus 2002: 158). To uphold the Nicene faith, the church decisively ruled out an incarnation where Jesus takes on only part of the body and soul composite that constitutes the human being.

Decades later, around the year 428, the patriarch of Constantinople, Nestorius, preached a sermon in which he denied that Mary was Theotokos (‘God-bearer’). It was impossible, and indeed offensive, so he argued, to suggest that God could be born of a woman. Mary, instead, should be understood as ‘Christotokos’ (‘Christ-bearer’), the one who carries the man Jesus to term, not the eternal Logos. According to Nestorius, the Logos assumed an ontologically complete human being, so that one could say that there are two individuals in Christ. Nestorius sometimes uses prosopa (‘faces, masks’) to speak of the Logos and Christ. In the following three years, Cyril, patriarch of Alexandria, campaigned vigorously against Nestorius’ teaching. For him, Nestorius compromised the identity of Jesus Christ as ‘one and the same’ as the Logos, the Word made flesh (see Cyril of Alexandria 1995; Wickham 1983; on the history see McGuckin 1994).

Cyril’s judgment, which is recorded decisively in his Second and Third Letters to Nestorius, was approved at the First Council of Ephesus, the third ecumenical council, in 431. This council and all that follow it introduced no new creed. In fact, the council forbids the composition of a new creed (DH: section 265). It claims to uphold the Nicene Creed and interpret it, so Ephesus I, and the faith as taught by Cyril, is understood to be the true interpretation of the Nicene faith. In this, the Council maintained, in the words of the Twelve Chapters, anathemas written by Cyril upheld as the teaching of the church in council:

If anyone dares to say that the man assumed ought to be adored and glorified along with God the Word and that he should be called God conjointly as one person with another […] and does not instead venerate the Emmanuel with one adoration and glorify him with one praise, since the Word became flesh, let him be anathema. (DH: section 259)

Nestorianism, then, is declared an invalid account of the incarnation. Rather, at the term of the incarnation, Jesus of Nazareth is one and the same as the Logos. This is the clear teaching of Nicaea, which speaks of ‘one’ Son who both is begotten from the Father in eternity and became flesh and dwelt with us in time. The grammar of Nicene theology suggests, as Ephesus teaches, that ‘the same is at once God and man’ (DH: section 257).

After Ephesus, Cyril and those sympathetic to him were able to achieve a measure of unity with the church in Antioch, some of whom had been supportive of Nestorius’ basic concerns. The two parties signed the Formula of Union in 433, but the goal of unity was elusive. In 449, Eutyches, an archimandrite of Constantinople, taught a highly unitive account of Christ that critics argued downplayed the distinction of humanity and divinity in Christ. Eutyches was condemned in 448, but due to the efforts of Dioscorus of Alexandria and supporters of Cyril’s vision he was rehabilitated at a council at Ephesus in 449.

The Council of Chalcedon was convoked by the Emperor Marcian to heal divisions that cut deeply through the fabric of the Empire in the 430s and 440s. The Definition of Chalcedon, produced at the Council in 451, was intended to set a series of terminological boundaries, or dogmatic qualifiers that must not be crossed (Daley 2018: 13). It is thus not intended as a speculative theological document, but only a dogmatic one (see the argument of Grillmeier 1975: 543–550). As Sarah Coakley and others have repeatedly emphasized in recent scholarship, the document leaves many questions unanswered, like the precise definition of hypostasis and physis (nature; Coakley 2002: 162–163; cf. Adams 2006: 54). These terms had already been hotly contested among ecclesiastical parties prior to Chalcedon, and would continue to be so after. In reply to Karl Rahner’s question about whether Chalcedon was the ‘end or beginning’ (Ende oder Anfang) of the dogmatic tradition on Christ, Brian Daley has recently argued that we should consider Chalcedon as a ‘crucially important way station, one of several’ in the church’s ongoing development of doctrine on the person of Christ (Daley 2018: 18; see Rahner 1961: 149–200).

While granting the modern hesitancy to say too much about what Chalcedon really tells us about the incarnation, careful reading of the Definition reveals a few important things. First, the Chalcedonian Definition of Faith provided a clear victory for Cyril’s approach to the incarnation while also adding some qualifications. The Cyrillian phrase ‘one and the same’ is repeated six times in the definition: the one who is born of the Father before all ages is the ‘same one’ who is ‘one in being with us as to the humanity, like unto us in all things but sin’ (DH: section 301). The Nicene faith received from the fourth century must be understood as descriptive of a single person, the Son, who ‘is not split or divided into two Persons, but he is one and the same only begotten Son, God the Word, the Lord Jesus Christ [...] as has been handed down to us by the creed of the Fathers’ (DH: section 302). The basic claim is that this man from Nazareth just is the eternal Word of God. Yet Chalcedon upholds that this one person exists ‘in’ two realities or ‘natures’ (en duo physein), terms that were heavily contested, but the Definition seems to claim that they refer to two kinds of reality that the Son has (namely, divinity and humanity). The Son is ‘in two natures’, first, ‘without confusion or change’ (asynchutōs, atreptōs). His mode of existence in two natures does not elide the distinction between divine and human realities, as the views of Eutyches and Apollinaris did. It thus rules out particular ways of construing a single-subject Christology: one that would result in a third substance (Eutyches), or an incomplete human reality in Christ (Apollinaris). Second, the Son is in two natures ‘without division or separation’ (adiairetōs, achōristos). Here the council rules out two Sons, the claim, whether desired or implied, of Nestorius. Christ’s activity is not to be understood as a conjoining of two agents acting together, but as one and the same actor acting in virtue of the two different sets of natural powers and activities that belong to him.

The Council of Chalcedon also approved as doctrinally normative the letter of Pope Leo I the Great (d. 461) to the Patriarch of Constantinople, Flavian, which condemned Eutyches’ teaching. For most of church history the letter has been controversial, especially among churches who do not receive the teaching of Chalcedon as authoritative and binding. Among the basic concerns is that Leo appears to affirm two agents in Christ, vindicating Eastern fears of a creeping Western Nestorianism:

The activity of each form is what is proper to it in communion with the other: that is, the Word performs what belongs to the Word, and the flesh accomplishes what belongs to the flesh. One of these performs brilliant miracles, the other sustains acts of violence. (Tanner 1990: 79)

Controversy over Leo’s Tome has not abated since it was written. There are many ways one could sort out what follows from its claims, and this is why the fifth, sixth, and seventh councils were necessary. Rowan Williams has recently argued that the Tome obscures more than it clarifies about the mode of union of Christ’s two natures, since it appears to speak of the hypostasis as distinct from the natures (Williams 2018: 86–87; cf. Beeley 2012: 272–284; Ratzinger 1986: 37–38). Robert Jenson has even accused the Tome of Nestorianism:

If this is not Nestorianism, it is something rather worse. The Son does the saving, the man Jesus does the suffering. The Son does the self-affirming, Jesus does the victim part. (Jenson 1999: 314)

This accusation, however, ignores the fact that just before Leo discusses the natural activities in Christ, he affirms, in agreement with Cyril, that ‘[t]he same one (idem) is true God and true man’, thereby denying Nestorianism. It is in this unity that the distinction of Christ’s two natures is not obliterated. This is in fact the context in which the controversial quote appears, and thus it is wrong and uncharitable to read Leo as supporting Nestorianism, even unwittingly.

Still, for many in the church the reception of Chalcedon’s teaching was difficult and burdensome, especially in how it appears to teach two acting agents in Christ. The struggle over the following centuries would be how to understand two natural actions, divine and human, in one and the same person, in a coherent way. The Nicene faith holds that there is only one agent, Christ, who is one and the same and the Logos, but after Chalcedon, how this agent Jesus acts needed to be clarified, since he possesses two distinct natures in virtue of which he acts. For example, after the council, Severus of Antioch (d. 538) held that Chalcedon’s language did not preserve the unity of subject that Cyril so desired (see Meyendorff 1975; for postconciliar concerns, notably in the work of Severus of Antioch, see Torrance 1988 and the history in Grillmeier 1995; Frend 1972). Today, the Oriental Orthodox churches do not accept the teaching of Chalcedon for similar reasons (on non-Chalcedonian Christianity, see Louth 2009).

3.3 Constantinople II (553) and Constantinople III (681)

The fifth ecumenical council (Constantinople II) was convened by Emperor Justinian I to conciliate some of churches that had trouble with the Chalcedonian Definition, by posthumously condemning the works of Theodore of Mopsuestia, Nestorius’ teacher Theodoret of Cyrus, and Ibas of Edessa, whose works had been compiled together into ‘The Three Chapters’. It ruled out various forms of dual agencies in Christ, whether they were perceived or real in the sources of criticism. The Council advances in the clarity of understanding by the affirmation that ‘one of the Trinity suffered in the flesh’ (DH: section 432), siding the Council clearly in Cyril’s understanding of the unity of Christ.

With the sixth ecumenical council (Constantinople III) we gain a clearer theological grammar for Christ’s agency in Chalcedonian terms, as one hypostasis or individual that has two distinct natures. Under the theological leadership of Maximus the Confessor (d. 662) in the decades prior, along with Pope Martin I at the Council of the Lateran (649), Constantinople III taught that this one of the Trinity, the Logos, who exists in two natures also possess two wills and operations or energies. The Council thereby draws a firm distinction between person and nature. Persons possess natures, which give them the powers necessary to carry out certain kinds of actions. Jesus Christ, as one person in two natures (cf. Chalcedon), therefore has two natural wills (or sources of action) and actions themselves. To claim that Christ had only one will and operation, as some opponents of Chalcedon had long argued, would collapse divine and human realities together in Christ (DH: section 558). Divine and human wills and actions are distinct in Christ, but they belong to ‘one and the same’, as the Council cites Cyril approvingly (DH: section 557).

Christ, then, can undertake two utterly distinct kinds of actions: create the world as God, and die upon a Roman cross as a man. Yet though he had two wills, he never willed contrary states of affairs via either nature. He cried out to his Father in the Garden of Gethsemane while his natural will, that power in him that helps him cling to life, shrank back in terror. As Maximus taught, he brought his human will in subjection to the divine will he shares with the Father and the Holy Spirit when he said: ‘Not what I will, but what you will’ (Matt 26:39; Maximus the Confessor 2003: 173–176; on Maximus’ Christology see Bathrellos 2004). This happens because this one of the Trinity, the Logos, exists in two natures, and yet he is always one and the same agent (see The Natures, Minds, and Wills of Christ in Christian Philosophy).

3.4 Nicaea II (787)

Ancient conciliar teaching on God and Christ comes to its fulfilment in the doctrinal pronouncements of the Second Council of Nicaea (787; on the development of iconodulism, see Brubaker and Haldon 2011; on the Council, see Nichols 1988). The presenting issue was iconoclasm: can Christians use icons in worship and devotion licitly? The iconoclastic synod of 754 argued that the issue was to a great extent christological: if Christ is depicted in an icon, then both of his natures, divinity and humanity, are depicted, or they are not. The Council, helmed by the iconoclastic Byzantine emperor Constantine V, declared that if both natures are depicted in the image of Christ then divinity can be circumscribed, which is false, but if divinity cannot be circumscribed, then only Christ’s humanity would imaged, and then Nestorianism would follow (Schaff 1955: 544).

The Council of 787 would reverse the decisions of 754 and argue that it is licit for Christ to be depicted and venerated in an icon (see Dumeige 1978; Giakalis 2005; Parry 1996; Roth 1981). During the second wave of iconoclasm after the Council, Theodore the Studite (759–826) defended the coherence of Nicaea II’s claims with the teaching of the prior ecumenical councils, especially Chalcedon. Theodore argues that Jesus is both uncircumscribed according to his divinity and circumscribed according to his humanity, and that applying contradictory properties to the same person does not require the properties he has in virtue of his two natures to ascribe those properties to the opposite nature (Theodore the Studite 1981: 22). That would be the Eutychian error: ‘If the properties of the things are mixed, then obviously their natures are mixed also’ (Theodore the Studite 1981: 94). Neither does circumscription render Jesus a mere man, the Nestorian error. The Logos, the second Person of the Trinity, took on an individuated human nature, or a particular human reality, which is truly his own in virtue of the hypostatic union. His possession of a human nature enables him to be depicted on an icon (Theodore the Studite 1981: 23, 93–94). He, the Logos, who is one and the same as the man Jesus, is perceivable on an icon, since images portray persons or hypostases and not natures. Theodore argues that only a robust iconodulism can be a faithful theology of the incarnation in agreement with prior conciliar teaching. In the icon of Christ, we truly depict the face of God, and all honour paid to the icon passes over to its prototype, or the one who is imaged.

The seven councils together teach that God took on flesh in Christ and became truly visible and tangible to us. He wills to uphold the universe as God and wills to die as a human being on the cross for our sins. He just is one of the Trinity who is also a human being, because he exists in two natures. The man from Nazareth just is the eternal Son, eternally begotten from the Father.

4.1 The incarnation and Christian worship

From the church’s inception, Christians have worshipped the human being from Nazareth, Jesus Christ. It was his claim to be the Son of God, making him worthy of worship, that led to his condemnation (John 19:7). Christian worship of Jesus is confirmed in early secular letters like Pliny’s letter to Trajan, where we learn that the early Christians sang hymns to Christ ‘as to a god’. The church’s early eucharistic prayers reveal the central place of Christ in worship. The third century Apostolic Tradition, composed in Rome by Hippolytus or those in the Hippolytean community as an ideal structure for worship, praises God ‘through’ Jesus Christ (Hippolytus of Rome 2015: 78). Early Christian worship manuals often contain this kind of causal language: Jesus Christ enables or brings about our praise of God the Father (see also the Didache, chapter 9, for earlier eucharistic prayers that employ similar language). Today, Catholics sing the Gloria hymn at every mass before the Liturgy of the Word, a second- or third-century hymn like the Te Deum that draws on the Gospel of Luke. The church offers Jesus worship:

For you alone are the Holy One,
You alone are the Lord,
You alone are the Most High,
Jesus Christ,
With the Holy Spirit
In the glory of God the Father

Christians as a community are defined by the praise of Jesus Christ, the incarnate Jewish messiah, together with the Father and the Holy Spirit. Jesus is both fully human and fully God, making him worthy of worship.

4.2 ‘He was made man, that we might be made God’: incarnation and salvation

The doctrines about God and Christ arise from the Christian experience of salvation. Khaled Anatolios has persuasively argued that the body of doctrine of the seven ecumenical councils ‘presumed and prescribed a conception of salvation as the deification of human beings through their graced inclusion into trinitarian life’ (Anatolios 2020: 168). The theology of the incarnation assumes that God has touched our flesh so that he might draw us into his very life.

In the wake of the Arian controversy, Athanasius and Gregory of Nazianzus after him argued for an orthodox account of the incarnation on the basis of the experience of salvation as deification. For them, salvation consists in the transforming and deifying union of the human being to God through Jesus Christ. For Christ to impart this gift to us, four things are necessary. First, he must be God, the Word of the Father who once was not flesh but who ‘became’ flesh for us and our salvation (John 1:14). Second, he must have maximally extensive contact with our flesh, in that the Word must touch every part of our being, both body and soul. As Gregory put it in his rebuttal of Apollinarianism, ‘what is not assumed is not healed’ (see section 3.2 above). Every feature of the human being has to be assumed by the Logos in time, except for sin, in order for this union to bring about our salvation (Heb 4:15). Third, this contact of flesh must be maximally intensive. Put differently, the union must be much higher than the deifying union that Christians have with the Lord by grace. For example, Thomas Aquinas argued that the most intense way that God can be united to a creature is hypostatic union (Summa theologiae III, q. 2, a. 10, ad 2). Fourth, Christ’s natures must retain integrity as utterly and irreducibly distinct; in being elevated by the hypostatic union, Christ’s humanity must not cease to be humanity in any way. In these ways the incarnation is connected to the Christian experience of salvation. When God touches every part of our flesh, we are healed.

Not all Christians hold to the view that salvation consists in the deifying transformation of the human person. Others hold that salvation consists primarily in God’s decision to remit a person’s sins for the sake of Christ and his passion, or a forensic account of justification (see e.g. Luther 1963: 121–147; Calvin 1960: 725–729; on Calvin’s notion of the twofold grace of justification and sanctification see Billings 2009). Protestant theologians have tended to prefer to speak of the transformation of the human person in more commonly biblical terms of ‘sanctification’, being made holy (e.g. 1 Thess 4:3–6; the text for deification is 2 Pet 1:4). For older Protestant theology, for the Christian to be made holy through his passion, Christ must be God. In this sense Protestant theology is arguably coherent with the ancient conciliar tradition.

One disputed point in theology is whether the incarnation was necessary for salvation. Patristic figures like Athanasius appear to suggest that salvation requires an incarnation (see Athanasius 2012), but it was medieval Latin theologians who interrogated the issue. Anselm (1033–1109) argued influentially that it was necessary that God become a human being to bring about salvation. In the thirteenth century, theologians tended to question Anselm’s argument. As Thomas Aquinas argued, if God is free, then multiple ways were available to him to save human beings (Summa theologiae III, q. 1, a. 2). Franciscan theologians Bonaventure and John Duns Scotus agree with Aquinas on this point, but develop radically different solutions (on the Christology of Bonaventure, see Hayes 2000; on Aquinas, see Barnes 2012 and Wawrykow 1998; on the literature on this particular question, see Hunter 2020; on the development of the debate in modern theology, see Van Driel 2008).

4.3 Incarnation and the Eucharist

The sacrament of the Eucharist has always been understood to depend at least in some way upon the incarnate Lord. Many Christians hold that the presence of Jesus in the Eucharist is, in some way, the presence of the very same body of him who walked through Nazareth 2,000 years ago. The basis for this is Jesus’ Bread of Life discourse in John 6: ‘Very truly, I tell you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you’ (6:53). In the Nestorian controversy of the fifth century, Cyril of Alexandria argued that Jesus Christ and the Logos are one and the same person because of the reality of Jesus’ lifegiving flesh in the Eucharist:

Whoever does not acknowledge the Lord’s flesh to be lifegiving and to belong to the very Word of God the Father but says it belongs to somebody different joined to him by way of rank or merely possessing divine indwelling, as we said, because it has come to belong to the Word who has power to vivify everything, shall be anathema. (Wickham 1983: 33)

This text was approved at the Council of Ephesus in 431 as the doctrine of the faith (see section 3.3 above). Since then, controversies over the meaning of the scriptural texts (including the institution narratives) and how to understand the metaphysical relationship of Christ’s human soul and body and his presence in the Eucharist remain controversial among Christians. The history of this reality is long and goes beyond the scope of this article, but the central question is: what is the relationship of Jesus Christ’s human soul and body in heaven and the sacrament on the altar? Catholic, Orthodox, and many Protestant churches agree that Jesus Christ is present in some way. Catholics and Orthodox hold that on the altar is just the very same body of he who walked in Nazareth 2,000 years ago, though Orthodox reject the language of ‘transubstantiation’ and its earlier relative ‘substantial conversion’ to describe how he is present, as taught by the Fourth Lateran Council (1215). Protestants differ widely among themselves on this point, but all have some position on the relation of Jesus’ human soul and body to the Eucharist (for a survey of the major historical options see Steinmetz 2008; see Luther’s mature statement of his position in his 1528 ‘Confession Concerning Christ’s Supper’ in Luther 1961: 151–372 and Zwingli in ‘On the Lord’s Supper’ in Zwingli 1953: 185–238; on Luther’s Christology, see Lienhard 1982; on the eucharistic controversies, see Cross 2019). Nearly all Christians reject the idea that the Eucharist is another incarnation, but most affirm that the incarnate Jesus is present on the altar in some way.

From the sixteenth-century debates on the Eucharist emerged the notion of the communicatio idiomatum (perhaps ‘application of names’), which became a prominent topic in the theology of the incarnation. This is a related concept to the doctrine of the incarnation. Prior to the sixteenth century, the communicatio idiomatum primarily referred to a theory about how to apply distinct names (or properties, from Greek idia) proper to the distinct natures of Christ to the person. Aquinas, De unione verbi incarnati a. 5, obj. 9 and ad 9; see the translation in Aquinas 2015). This text would have been known to Aquinas through the eleventh-century Latin translation of Burgundio of Pisa. The Damascene writes of the incarnation:

The Word makes human things his own (sibi, Gk. idiōn), because what is proper to His sacred flesh belongs to Him; and the things which are His own He imparts (Latin tradit, Greek metadidōmi) to His flesh, because of the mode of exchange (Latin retributio, Greek antidosis) on account of the mutual immanence of the parts and the hypostatic union. And because He who was one and the same who did both divine and human things with either form in communion with the other, therefore, the Lord of Glory is even said to have been crucified, although His divine nature did not suffer; and the Son of Man is confessed to have been in heaven before his passion, as the Lord Himself has said. (John Damascene 1958: 274–275)

At the end of this passage the Damascene emphasizes that what is ‘communicated’ to the Word are names or functions proper to his distinct natures (e.g. ‘The Lord of Glory is even said to have been crucified’ [on account of his human nature]). The communicatio idiomatum is, therefore, primarily a lexical-semantic theory about how to say things of Christ appropriately (to see the extension of this idea to medieval theories of reduplicative propositions in Christology as found in Aquinas, see Moser 2020).

As the sixteenth-century eucharistic debates progressed, however, the description ‘communicatio idiomatum’ began to be used to refer to an ontological theory about the consequences of the incarnation. If Christ is truly God and truly a human being, argues Luther, then he must be omnipresent in his humanity. To say otherwise would be to divide the person of the Word and thereby deny the truth of the hypostatic union (see Luther 1961: 218; on Luther’s writings that address the incarnation, see Zachhuber 2017). Theologians in the medieval period had debated the consequences of the incarnation on various topics like the extent of Christ’s human knowledge. As far as the author of this article is aware, however, no one prior to Luther argued for the presence of Christ’s flesh on the altar because of the sharing of his humanity in divine causal powers. The Fathers, like Cyril, speak of the lifegiving flesh of Christ, drawing on the Bread of Life discourse in John 6 (e.g. anathema 11 of Cyril’s Third Letter to Nestorius, in Cyril of Alexandria 1995: 32–33). But Cyril makes no appeal to an ontological theory that explains why Christ’s flesh is present or spiritually nourishing.

Reformed theologians disagreed with Luther and argued that the Lutherans do not distinguish the natures and powers in Christ properly. Tracing out the full extent of this debate goes beyond the scope of the article, but they have exerted a profound influence on the development of Christology. In modern theology, then, ‘communicatio idiomatum’ can refer either to the logico-semantic theory of predication or the ontological theory of how Christ’s human nature shares in his divine power.

5.1 Recent Catholic theology

Catholic theology has tended to affirm the teaching of Chalcedon and the ancient conciliar tradition in the face of modern criticisms. Recently, Pope Pius XII’s Sempiternus Rex Christus (Christ the Eternal King), issued on the 1500th anniversary of Chalcedon, is a particularly vigorous example. The ordinary magisterium has continued to regulate christological teaching deemed errant, as in 2005 when the Congregation (now Dicastery) of the Doctrine of Faith issued a notification on the works of Fr John Sobrino, SJ, whose liberation theology-inflected Christology arguably downplayed the divinity of Jesus. However, Catholic theologians have not been hesitant to take modern questions head-on.

In the middle of the twentieth century, Karl Rahner and Hans Urs von Balthasar emerged after the Second Vatican Council, offering two strategies for engaging modern critiques of traditional theology. Rahner sought to develop an account of the incarnation that takes modern epistemic categories as basic. All human knowledge and experience happens within the horizon of what Rahner calls ‘transcendental experience’, or pre-thematic awareness, which makes our knowledge of the world possible. Included in this experience is the hope that we will find an absolute saviour who meets our deepest needs. For Rahner, this saviour must be a historical person (Rahner 1978: 20, 208–212; on Rahner’s Christology, see Marshall 1988). Von Balthasar approaches the incarnation taking seriously the logic of scripture and the tradition as first-order, not human experience. For Von Balthasar, the redemptive death of Christ is unique and goes beyond any attempt to account for it as a new ‘existential’, in Rahner’s terms, an account of a human being who engaged with death in a superb manner (Von Balthasar 2005: 137, 146–147). More recent theology, following in von Balthasar’s line, has seen a renaissance in the study of patristic and Thomistic Christology. These Catholic theologians think of the ancient traditions of the church as generative for engaging modern questions (see especially White 2015).

5.2 Recent Protestant theology

Since the Reformation, a good deal of Protestant theology maintained a standard traditional picture of the incarnation, even where intellectual streams following Schleiermacher departed from it (on Reformed theology in particular, see Edmonson 2004; Heppe 1950: 410–447; Muller 2008; Willis 1966). Ever since Karl Barth published his explosive Romans commentary, Protestant theology has for the most part tended to foreground the traditional teaching of the incarnation, even if aspects of it are revised. Barth remains the most influential. Like von Balthasar, Barth holds that scripture has a basic logic that must be held if Christian theology is to be accountable to the Word of God as God reveals it. In particular, Jesus Christ’s incarnation reveals what divinity is: ‘The meaning of His deity – the only true deity in the New Testament sense – cannot be gathered from any notion of supreme, absolute, non-worldly being. It can be learned only from what took place in Christ’ (Barth 1956: 177). The incarnation reveals ‘the freedom of [God]’s divine love’, embracing divinity and humanity together while transcending them (Barth 1956: 187). Barth opened up space for theologians to recover a theology of preexistence and incarnation that proceeded from the logic of scripture. Among German theologians, Barth’s intuition has been developed in distinct ways by Jürgen Moltmann (1993), Wolfhart Pannenberg (1977), and Eberhard Jüngel (1983). Among contemporary Protestant evangelical theologians, classical pictures of the incarnation are making a comeback (e.g. Webster 2015) as greater awareness of older Protestant sources makes its way through English-speaking scholarship.