In yesterday’s post On the Importance of Doing and Debating Theology Theologically, I argued, with reference to church fathers Irenaeus, Tertullian, and the pro-Nicene theologians, that the interpretation of Scripture regarding central Christian doctrines such as the Trinity and the incarnation were firmly established on the basis of theological versus simply exegetical argumentation. That is to say, the church fathers who opposed the various early heresies, such as Gnosticism and Arianism, did so by appealing not only to Scripture but also to the regula fidei, the essential truths of the gospel understood in terms of the inherent theo-logic that binds together the occasional documents that make up the biblical canon into a coherent whole. This inherent theo-logic, as the church fathers believed, was ultimately Scripture’s witness to God’s self-revelation of his Triune being and action in Jesus Christ and by the Holy Spirit.
Since even the heretics employed Scripture to support their biblical interpretations, the fathers realized the futility of simply engaging in a back-and-forth war of biblical quotations and thus the necessity of penetrating so deeply into Scripture’s inner logic that they would be able undermine the very foundations and assumptions that gave rise to those heresies in the first place. This led them, at times, to articulate biblical truth using non-biblical language and lines of reasoning, not because they were asserting their word as authoritative over Scripture, but rather because they realized that theological clarity and precision required terms and arguments capable of laying bare the true meaning of the biblical words and concepts over against heretical obfuscation. For example, both the pro-Nicene theologians and the Arian heretics affirmed Jesus as the Son of God, where they differed was how they defined the nature of the Son of God. Therefore it was necessary to apply the non-biblical term homoousion and its attendant concepts in order to clarify and safeguard the truth, indispensable to the gospel, that Jesus Christ as the Son of God is fully equal to and one with God the Father eternally in essence.
What is important for us to understand is that driving these early conflicts was not simply the desire to maintain the integrity of abstract statements about, for instance, the full deity of Christ, as though the issue at stake in this particular debate had strictly to do only with making sure that the church affirmed against the Arians that “Jesus Christ is homoousion with God the Father.” Rather, underlying the homoousion was an entire nexus of truths, not only christological but also and primarily soteriological, that the homoousion was intended to protect. The church fathers recognized that a denial of the full divinity of Christ was not merely a christological error but that it would have had serious and damaging consequences for the Christian faith as whole.
In what follows, Fred Sanders helpfully explains a bit of what was at stake in the fourth century disputes concerning the divinity and humanity of Christ and the motivating rationale behind the words and phrases designed to preserve these truths in the most important creed of Christianity – the Nicene-Constantinopolitan Creed.
First Council: Nicaea I, in the year 325. As all the later councils are at pains to attest, the Council of Nicaea is the most important of the ecumenical councils. The heresy that provoked this epochal council was Arianism, the teaching that the preexistent Logos who took on flesh in the incarnation was not God, but a great and exalted creature. Since he was the Son of God, Arius argued, he must have come into existence from nonexistence, and prior to that he must not have existed. The Arian Christ is certainly a supernatural being, but just as certainly he is not actually divine. Arianism was rejected by the 318 bishops gathered at Nicaea under Emperor Constantine.
Because Arius and his supporters were capable of making most scriptural language agree with their doctrine, the orthodox party pressed the extrabiblical term homoousios into service, meaning by it that the Son of God is of the same (homo) substance (ousia) as God the Father, or consubstantial with him. The goal of the Nicene theologians (including the rising generation that included the great Athanasius of Alexandria) was to assert the complete deity of Jesus Christ in a clear and unequivocal way, which they did by placing this term into the creed that was produced at this council, calling Christ “the Son of God, begotten from the Father, only begotten, that is, from the substance of the Father, God from God, light from light, true God from true God, begotten not made, of one substance (homoousios) with the Father . . .” Lying behind this undertaking was a vision of what salvation entails: personal reconciliation with God and participation in God’s own life. With that view of soteriology in place, the implicit soteriological axiom driving Nicaea and the entire conciliar theological tradition downstream from it is: God alone can save.
Second Council: Constantinople I, in the year 381. The main thing the fathers of the first Council of Constantinople would want us to say about their work is that they reaffirmed the Council of Nicaea…They revised [the Nicene Creed] slightly by extending the article about the Holy Spirit and tightening up the terminology…It is the faith of Nicaea as revised and extended in the creed of 381 that we commonly call today the Nicene Creed. Aside from this and the extended pneumatological article, along with an anathema against those “fighters against the Spirit,” the Pneumatomachians, did Constantinople I teach anything new?
It did take a stand against a new heresy, Apollinarianism, which was in some ways a kind of opposite error from Arianism. Apollinarius of Laodicea was a theologian who, beginning with the thought of the eternal Logos who is consubstantial with God the Father, described the incarnation as the Logos operating the physical body of Jesus. The human nature of Jesus Christ, on the Apollinarian account, was only a human body with no rational soul…This “God in a bod” Christology has the obvious defect of recognizing the full deity of Christ at the expense of his full humanity. Apollinarianism was anathematized in the first canon of the council.
Against Apollinarianism, the fathers of Constantinople had to confess the full humanity of Christ in a new, clear, and soteriologically relevant way. Behind the rejection of Apollinarianism was a vision of salvation represented by the soteriological axiom: “What is not assumed is not healed.” This axiom, articulated by Gregory of Nazianzus (who chaired part of the proceedings), presupposes that the Son of God saved humanity by “taking on” or “assuming” human nature into union with himself. Everything in human nature needs to be saved, so everything must be taken into union with Christ. In this light, if Christ had no human soul, the human soul is left unredeemed. It is worth nothing the way Constantinople I argues for a scriptural teaching by using a new line of argument not directly advanced by the Bible itself.
Taken together, Nicaea I and Constantinople I establish, using new terms and lines of argument, the full divinity and the full humanity of Christ. In both cases, the councils do this not as a speculative exercise, but under the guidance of soteriological axioms that trace the logic of redemption in Christ: God alone can save us, and what is not assumed is not healed.
The point that I want to make from this is simple: inasmuch as we affirm the Nicene-Constantinopolitan Creed – that is, inasmuch as we believe that the Nicene and Constantinopolitan fathers rightly articulated the absolutely fundamental gospel truths that Jesus Christ is fully divine in his eternal essence and relation to the Father and that he is fully human in his assumption of the total ontology of Adamic humanity – then we must understand that we are committing ourselves to more than simply abstract statements such as “Jesus is fully divine” and “Jesus is fully human”. In reality, we are committing ourselves to the “soteriological axioms that trace the logic of redemption in Christ: God alone can save us, and what is not assumed is not healed.” These axioms themselves contain oceans of theological meaning, for they condense in a few words massive swathes of the biblical witness to God’s act of revelation and reconciliation in Jesus. It seems to me that it would be inconsistent or disingenuous for us to affirm the Creed and its explicit statements without affirming the implicit theological content that those statements were intended to symbolize and protect.
Just to provide a couple of examples of what I mean. The homoousion does not merely assert that Jesus Christ is fully divine and equal to God the Father. In its original creedal and historical context, it was designed to preserve the biblical truth that the being, will, and act of Jesus Christ in history – from his birth to his death, resurrection, and ascension – are identical with the being, will, and act of the Triune God from all eternity. Arius taught that the Son, being a creature, could neither possess nor communicate knowledge of the Father. Contrary to this, the pro-Nicene theologians argued that since Jesus is homoousion with the Father, the God that we see and know in him is the God who exists from all eternity in unapproachable light. The homoousion ensures that the God we contemplate in Jesus Christ is, simply put, God as he is in himself without distortion or remainder. Any theological view or statement, then, that denies this fundamental truth constitutes a de facto denial of the homoousion – even if it does not explicitly deny that Jesus is fully divine. An example of this would be limited atonement: since Christ’s death was intrinisically sufficient to save all, the idea that there is another decree, hidden in the recesses of eternity, that limits the design of that death to the salvation of only a few, effectively posits a God that is hidden behind or different from the God that is revealed in the cross of Christ. Therefore, limited atonement violates, in effect if not in principle, the essential content of the homoousion.
Moreover, the soteriological framework behind the orthodox defense of Christ’s full humanity guides and governs our understanding of his atoning work. Any theory that would define the atonement in terms of a merely external transaction, payment, or satisfaction of debt would not do full justice to the reasons for which the early church insisted that Christ must be fully human. How so? Because the axiom ‘the unassumed is the unhealed’ intimates a decidedly internal and incarnational understanding of the atonement. The struggle against Apollinarianism was fueled by the realization that if Christ had not assumed one particular aspect of humanity in his incarnation, then that aspect would have remained unredeemed. In other words, church fathers were convinced from Scripture that Christ accomplished redemption incarnationally and vicariously in himself on behalf of all humanity. Had he merely offered a payment for human sin, this would not have sufficed to deal with the actual corruption of human nature. This is why, as Gregory of Nazianzus so ardently contended, that unless Christ assumed our nature into healing union with himself, then we could never have been fully redeemed. Atonement was not a work that was accomplished, so to speak, outside of Christ or over his head, but rather within himself as the representative and substitute of all humanity.
Among many other things, these are the central truths to which we commit ourselves when we profess the Nicene-Constantinopolitan Creed. It is not enough simply to state that “Jesus is fully divine and fully human” and leave it at that without taking the time to deeply grasp the underlying theo-logic that this statement was originally intended to symbolize and safeguard. It is not enough to simply affirm this truth in the abstract and then think that we are free to formulate the rest of our theological knowledge is any way that we see fit. Rather, these truths, which the early church recognized to be so vital and necessary to the gospel, provide the standard by which we can evaluate the fidelity or infidelity of our interpretations of Scripture in accordance with God’s definitive self-revelation in Christ. Without this regula fidei we will drift, as the church fathers knew all too well, without a compass in a sea of exegetical possibilities, any number of which lead us into a shipwreck of faith. Therefore, may we relentlessly seek to penetrate ever deeper into the marvelous depths of Scripture’s inner theo-logic by listening to and learning with the great cloud of witnesses who faithfully defended and passed on to us the biblical faith once and for all delivered to the saints.
 Sanders, F., ‘Introduction to Christology: Chalcedonian Categories for the Gospel Narrative’ in Jesus in Trinitarian Perspective: An Introductory Christology. Nashville: B&H Publishing, 2007. pp.18-19