Almost immediately following Christ’s death, resurrection, and ascension, the church found herself subject to infiltration by heretics and false doctrine. While these heresies did not focus exclusively on the person of Christ, most of them did, and early Christian theologians labored to respond to these challenges in order to articulate a logically coherent, biblically faithful account of Christ’s identity.
The question, “Who do you say that I am?” first posed to the apostle Peter by Christ himself (Matt 16:15), soon became a question of massive importance for the church as she sought to rightly understand Christological doctrine amidst the ever encroaching opposition. These heresies, however, did not ultimately serve to weaken the church’s doctrine of Christ; rather, as Harold Brown has noted, God used these challenges help his church clarify, refine, and crystallize her understanding of Christ’s identity as it was revealed in Scripture.
The Need for Clarity About Christ’s Identity
But why was such clarification so crucial? First, because Scripture places Christ at the very center of God’s work of redemption. Not only could we multiply explicit biblical statements that make this clear (e.g. Luke 24:44ff; Romans 3:21-26; Titus 2:13-14), but the entire structure of the Bible with its promise-fulfillment motif, shown especially through typology (persons, events, and institutions in the OT, fulfilled by Christ in the NT), finally culminating in the death and resurrection of Christ, demonstrate that the identity of the Son of God and his relation to God’s plan of redemption is of central importance throughout Scripture.
Second, one’s salvation hinges upon whether or not one properly understands and believes specific truths about Christ’s identity. For example, the apostle John, combating Gnostic interpretations of Jesus’ humanity, classified those who denied the reality of Jesus’ human nature as the “spirit of the antichrist” (1 John 4:2-3). Jesus himself told the unbelieving Jews that their refusal to believe in his deity would result in their condemnation (see John 8:24).
Third and related, by placing the identity of Christ within a biblical-theological framework of God’s plan of salvation (with four important plot movements: creation, fall, redemption, new creation) we note that human redemption is dependent upon a Savior who is not only fully God and thus able to fulfill divine demands of justice, but who is also fully human and thus able to truly stand in the place of sinners as their representative and substitute.
Finally, rightly understanding Christ’s identity is essential for proper Christian worship. Hazy, ambiguous visions of Christ do not bring glory to our Savior, nor do they satisfy our souls. We need clarity about the person of Christ for the sake of his glory and our spiritual joy.
The Counsel of Nicea (325 AD)
Intense debate over the incarnate Christ emerged as the Church sought to articulate Christ’s relationship to God the Father in relation to the Father’s deity. The counsel of Nicea (325 AD) affirmed that Jesus Christ was of the same substance (homoousious) of the Father and that the Son was begotten from the Father (“Light of Light, very God of very God”), yet uncreated.
These statements concerning Christ’s deity were directed at Arianism, a serious heresy named after its primary proponent, Arius (250-336), that argued that Christ was subordinate to God the Father in nature. This position stated that the Son was merely ‘similar’ to the Father (homoiousios) not of the same substance (homoousious). Arius argued that God the Father alone was the only self-existent, uncreated being in the universe; the Son was the highest of all created beings and, perhaps, shared more of the Father’s nature than any other human being; he was, however, not equal to the Father with regard to deity. Nicea answered directly these issues raised by Arius and his followers.
The Council of Constantinople (381 AD)
Following Nicea, the church, having established the unity of the Trinity, now sought to guard the affirmations given in the Nicene creed from modalism—the notion that the one God manifests himself in three different forms or “modes” throughout redemptive history. Here, the council concluded that God was one ousia (being; homoousia, “same being”), who existed in three distinguishable hypostases. The three members of the Trinity, therefore, were to be distinguished in terms of internal relationships or properties of persons. The Father possesses the property of unbegottenness; the Son possesses the property of begottenness; the Spirit possesses the property of procession. Each member of the Trinity, however, shares the same ousia.
The affirmations given at the council of Constantinople, therefore, sought not only to restate and endorse the declarations given at Nicea; they also sought to clearly refute modalism, while also including important statements about the Holy Spirit within an “updated” creed. The Trinity was now understood as one essence in three persons.
The Chalcedonian Creed (451 AD)
Having established the pre-existent deity of Christ, the church now faced a new challenge: How was she to explain how the eternal Son of God became incarnate? More specifically, how was she to understand the unity of the two natures in the one person of Jesus Christ? Debate over this issue would eventually lead to the forming of the Council of Chalcedon and writing of the Chalcedonian Creed (451 AD). This creed would affirm several important aspects of the incarnation.
First, it would reaffirm that Christ was both perfect deity and perfect humanity—that Christ was both truly God and truly man. In this affirmation, the Chalcedonian creed would remain in line with the previous creeds by rejecting Arianism (by stating that Christ was truly God) while also refuting Docetism (by saying that Christ was truly a man and did not only appear as a man). It is this affirmation that lays the foundation for the remaining affirmations in the Chalcedonian Creed.
Second, it would affirm that Christ’s humanity consisted of a rational soul and body. Apollinaris (310-390 AD) had previously argued that the eternal Logos replaced the human soul in the incarnation, and that the eternal Son only took on a human body. Strictly speaking, Apollinaris affirmed that Christ had a “sensitive” soul, but the Word of God was in that soul in place of the intellect and the mind. Chalcedon answered this challenge by affirming that the eternal Son took a truly human nature consisting of a body and a soul, and that this soul was “rational”—i.e., included a human intellect and mind.
Third, the creed would assert that the unity of the two natures “concurred” in one person. Nestorius (386-451 AD), bishop of Constantinople, had argued prior to Chalcedon that Christ consisted of two separate persons. In the incarnation, Nestorius argued, the divine person—the Son—took upon himself a human person so that in Christ, there was the unification of the two distinct persons. This view would be unable to explain the actual unity of the persons and would also leave the door open for another related heresy, Adoptionism.
The creed, therefore, made an important distinction between nature and person and stated that the person of the incarnation (the “I”; the “subject”) was the eternal Son. In the incarnation, the one person of the Son now existed in two natures: divine and human. Furthermore, by stating that the two natures “concurred in one person and one subsistence,” the creed stated that ‘person’ and ‘hypostasis’ were the same thing and that ‘person’ was not to be derived from ‘nature.’
Fourth, the creed affirmed that Christ’s two natures were truly unified but remained distinct, “without confusion, without change, without division, without separation…the property of each nature being preserved.” Monophysitism, articulated by Eutyches (378-456 AD), a leader in Constantinople, was a view that Christ had only one nature. According to this position, the human nature of Jesus had been absorbed into the divine nature thus creating a fusion of the divine and human natures, subsequently creating a whole new nature. In this view we note immediately problems related to both Christ’s ability to satisfy divine justice (he is not fully divine) and to stand as man’s perfect representative and substitute (since he is not fully human). Chalcedon rejected this heresy.
Conclusion
The Chalcedonian creed is a rich, theologically-rigorous, carefully-nuanced document that determined the parameters within which further Christological reflection could continue. As we’ve seen, the Chalcedonian creed was built upon other creeds (e.g., Nicene) but it made genuine dogmatic advancements as it answered heresies specific to the person of Christ. We can thank God for his work in solidifying these doctrinal categories through the careful work our theological forebears.
From the Study 
Excellent post.
Food for thought: It would seem to me that the Chalcedonian Creed, rich as it is, would be agreed to by a demon, who would know and believe all that the creed states. Thus, it is vital for Christians to know that recitation and belief in a creed is not tantamount to saving faith. There MUST be personal repentance and faith in Christ’s substitutionary atonement for the remission of sin for one to be saved. We are not saved by creeds; we are saved by the gospel of Jesus Christ.
Thanks for this helpful overview of these 3 major ecumenical councils
Great reading your bloog