As we have debated the doctrine of Trinity doctrine over the past few years, so now I think we are about to enter a time of renewed debate about Christology. The reason is twofold. First, we have forgotten about theological anthropology whose language provides the linguistic and metaphysical framework for the incarnation. Second, we have underappreciated doctrines like immutability and impassibility, which stand at the very heart of Christ’s identity (and thus the Gospel).
I will explain what I mean in more detail below, but in short Christology has lost its twofold basis. And with such loss, almost every other doctrine of Christianity suffers because such doctrines require Christology to make sense.
Many Christians no longer affirm the key to classical Christology doctrine, namely, that the infinite, immutable, impassible one unites to finite, mutable, and passible humanity. Some Christians even affirm neo-apollinarianism. And rarely do churches proclaim Christology from the pulpit (at least in its more theological form).
So I think it is worth remembering some of the patterns of theological and scriptural thinking that Christians have used over the years. If we remember the past, we might just overcome the looming civil war that is coming on the horizon.
The Meaning of “Become”
We need to start somewhere, and we might as well start with some of the key Christological debates over the years. When it comes to such debates, it can be helpful to consider how the various theological positions might have understood the word “become” in the phrase “Word became flesh” from John 1:14. It at least provides a conceptual rung to hang our thoughts.
In other words, in the following, I want to show how the way in which one views Christ’s two natures relating to another will make one trend in certain theological directions.
First, some advocated that the Word came into flesh, in the sense of indwelling flesh substantially. Such a view trends towards docetism, various forms of gnosticism, and paulicanism (Paul of Samosata).
Second, some advocated that the Word changed into flesh, in the sense of mixing together to form one nature. Yet such advocates only did so for the sake of making an argument ad absurdum since God cannot change; and so they found it obvious that the Son of God could not be divine like God is. This view trends towards arianism and eunomianism.
Third, some advocated that the Word substantially unites divinity and flesh according to nature, in the sense of completing one single subject who is Christ. Such a view trends towards apollinarianism, eutychianism, and miaphysitism.
Fourth, some advocated that the Word seemed to become flesh but really the Word and the flesh maintain their distinct properties without any natural union. Such a view trends towards nestorianism.
Fifth, some advocated that the Word became flesh by assuming flesh into the Word, in the sense of the Word uniting divinity and humanity into himself personally. Such a view trends towards chalcedonian dogma.
Each view attempts to define what happens when the Word becomes flesh. When it comes to the scriptural passage itself, the grammatical and near scriptural context of John 1:14 really provides no easy answer since the statement “the Word became flesh” occurs without explanation.
However, earlier and later passages in John do provide theological reasoning for which option best accounts for what Christ is and, as I shall note, does.
Jesus claims that if one has seen him then one has seen the Father (John 14:9). He also claims that he and the Father are one (John 10:30). Such statements reflect the prologue’s statement that the Word is God (John 1:1) and that the Word reveals God (John 1:18).
These statements of divinity and oneness along with the fact that the Father and Word (or Son) somehow differ from another leads to a particular problem implicitly evinced above. First, how can God be one if two names (Father and Son) make up the definition of God? And second, since God by nature must be immutable, then how can one God become flesh?
In this respect specifically (and not generally), Arius followed the right line of logic. God changing into flesh would entail that he is not God. And so “became” in John 1:14 must take on a different sense than transformation or else we lose God.
Communication of Idioms
The solution is that “became” does not mean that divinity transforms into humanity. That not only would make God not God but also Jesus not human. If God mixes himself into flesh, and that mixture produces a complete Christ, then whatever Christ is, he is neither God nor human in any normal way.
So theologians attempted to parse out how Christ can genuinely descend from Adam and yet also descend from heaven. Nestorius and others attempted to say that the union of divinity and humanity in Christ preserves its integrity completely. As Weinandy recounts, in Nestorius’ scheme both human and divine natures have their own perspective persons (persona), yet Christ as the amalgamation of these characteristics can be said to be one person (prospon).
As Weinandy also points out, Nestorius could not escape therefore the conclusion that Christ as a single person was really a linguistic construct or phenomenological description. There was no metaphysical depth to the name Christ. He was simply a word that represents two distinct natures united without mixture.
The problem here is obvious. Nestorius’ affirmation of the single subject of Christ has no meaning beyond itself. It is simply a linguistic summary. Further, Nestorius cannot really account for how a single subject who is both divine and human can die. For when Christ died, in some sense we must conclude that God died. Of course, how we do so matters since there must be a way to preserve the full reality that God is immortal and man is mortal and yet somehow the God-man Jesus Christ died for our sins.
And so Cyril of Alexandria and others after him rejected the Nestorian paradigm. Nestorius’ view logically required, Cyril thought, that Christ was two persons. And that’s absurd. He is one person.
The technical language he preferred included that Christ became one subject from two natures, although he used various idioms and phrases. Yet his main point was that Christ remained one subject from two natures.
Later theologians crystallized Cyril’s affirmation of Christ as a single subject. They claimed that Christ united two natures according to his Person. That is, the Word assumes to itself human flesh in the incarnation. The Word as the Second Person of the Trinity provides the essential unity, making Christ one substantial unity.
Thus, Scripture and Christians can and do affirm things proper to divinity and humanity to Christ’s Person—the Word. The Word became flesh therefore by taking flesh into his Person.
In Christ, two natures are in and through one person—the Word. All of this is a roundabout way to affirm how Scripture talks about Jesus. He often carries divine attributes; at other times very human attributes. In both cases, the one Christ may have both because the idioms proper to each nature communicate in the Person of the Word.
The Personal Union
The manner of the personal union still bears further thought since Christians intuitively desire to have some metaphysical weight behind their worship. What does it mean for humanity and divinity to unite in the Person of the Word?
Herein lies the need to articulate anthropology with some specificity. Humans comprise both material and immaterial properties, body and soul. We are the irreducible sum of these two parts, which make up a human being. So for Christ to be human, he would need both nerves (blood) and a human will (soul).
This is where Apollinarius makes a mistake. He wants to preserve the single subject of Christ and the nature of God, but he does so understanding the Logos’ assumption of the flesh as soul and body unite to make a complete human. So Christ takes the Logos (who is spirit) and unites himself to flesh (human nature) without a clear place for a human soul.
In particular, Appollinarius wants to affirm the Logos takes the place of the highest property of the soul, the mind or nous. In this sense, I suppose he sees the Personal union as allowing for a true humanity to unite with the Logos.
But as Gregory of Nazianzus will complain, Christ needs to be fully human. He needs a human nous, or else how can he heal our human nous? The noetic effects of sin will remain. Thus, we enter into the soteriological dimension of the Personal union.
Union with Christ
Christ’s union of humanity and divinity is unique in history. Yet the way in which Christ lived as the God-man shows us what it looks to live as a redeemed human and in fact how Christ saves us. In short, Gregory and others see Christ’s entire life as substitutionary and redemptive.
Christ not only dies for our sins, but he lives to redeem what Adam lost. He shows us how to live and heals in himself what is sick in us. And so when we believe, we unite to Christ by faith. The Spirit then mediates the blessings that Christ has gained through his perfect life.
In this way, had Christ no human nous, then he would not reverse Adam’s course since he would not be in Adam as a human descendent. Yet he is fully human, and so he represents us as the perfect human being, the model for life, and the guide to God.
How we talk about Christ’s union matters for the salvation of the human race. Christology by definition issues forth our salvation. Indeed, it also, as noted, explains how the Holy Spirit can indwell us as he did Christ since we become one new human being in Christ.
It further then defines the church as the body of Christ. So Christology leads to soteriology, pneumatology, and ecclesiology not to mention anthropology since Christ alone in this world shows us how to be genuinely human.
And in this latter regard, we must affirm with Maximos the Confessor that the Logos unites to a rational and noetic human nature with every idiom proper to humanity.
I wrote this as a sort of enchiridion (guidebook) for our times. Soon, the Christological civil war will be upon us. And I hope that this admittedly short guide can provide the theological trajectories and memories that can help us to joyously affirm the Word who became flesh for us and for our salvation.