Christological heresies seem to be unending. People seem to have more problems in dealing with the nature of the person of Jesus Christ more than most other Christian doctrines. Is Jesus God? Is Jesus human? Is he both? If he is both God and man, how can we understand one person having a dual nature? Does Jesus need to have a dual nature in order to save humanity? Can I identify with Jesus if he was truly a God-man? Does Jesus really need to be divine in order to save? In response to such questions, this chapter has a dual objective: (1) articulate orthodox Christology as it emerged in response to historical Christological heresies, and (2) demonstrates how compromising any point of orthodox Christology means forfeiting the efficacious work of Christ. Any understanding of Jesus Christ that deviates from orthodoxy promotes a Christ that cannot truly redeem humanity.
Historical Christological heresies can be divided into two camps. First, there are heresies that deny either the humanity or divinity of Christ. Ebionites (second century) and Arians (fourth century) both denied that Jesus was divine. Docetists (late first century) denied the humanity of Christ by explaining that Jesus was only human in appearance. The second camp confirmed Jesus’ dual nature (unlike the first camp), but fell into heresy regarding certain nuances of Christ’s dual nature. Appollinarians (fourth century) denied the completeness of Jesus’ humanity by stating that the divine Logos took the place of the human mind. Nestorians (fifth century) denied the unity of Christ’s person by arguing that Christ’s human person was dominated and controlled by the divine. Eutychians were monophysitists – believing that the combination of Christ’s humanity and divinity merged to create a new, third nature. Modern Christological heresies are typically repeats of these earlier Christological heresies in one form or another (House, Wayne H., 1992).
The consideration of both of these heretical camps underlines the fact that orthodox Christology must properly treat two dynamics: (1) the dual nature of Christ, and (2) the personhood of Christ. Concerning the dual nature of Christ, orthodoxy Christology maintains that Jesus must be one hundred percent God and one hundred percent human. Concerning the personhood of Christ, while Christ has a dual nature, he must only be one person. If either of these components are compromise, then the work of Christ is no longer efficacious.
Christ must be one hundred percent God and one hundred percent human. Jesus must have the divine substance for a series of reasons. The priority reason for the necessity of the deity of Christ is that he is unable to forgive humanity of offenses accrued against God if he himself is not divine. Sins committed by humanity are personal transgressions against God. Christ then, is unable to forgive humanity on behalf of God if he himself is not God. Also, if Jesus were not God, he cannot redeem humanity as God. Only God (again, not an angel) is capable of delivering humanity from its condition. Therefore, forfeiting the divinity of Christ means his salvific work is not efficacious. Forfeiting Jesus’ divinity is also to go against what is clearly taught about Jesus in the inspired scriptures.
In order for Jesus to redeem humanity, he must be human (Hebrews 2:14; 1 John 4:1-3). If Christ is not human, than he is unable to substitute his own life on the cross for the sins of humanity. It is humanity (not an angel) that owes the living God its life for transgression of the universal moral law. Thus, the doctrine of substitutionary atonement falls apart if Christ is unable to genuinely represent humanity and its offense before God. Also in correspondence to the necessity of Christ’s humanity is the deliverance from the power of sin for humanity through his resurrection. If Christ was unable to sin, then his innocence (which is necessary for the substitutionary atonement) is illegitimate. It is only if Christ was truly tempted that he is able to deliver humanity from the dominion of sin. If Christ wasn’t truly human (or unable to sin), then he cannot be a true substitute for humanity.
What of the personhood of Jesus? It has been argued that the dual nature of Christ automatically results in a dual mind of Christ. As the mind is typically represents personhood, was Christ two persons? That is, how could Christ have had to natures, yet be one person? The answers to these questions continue to undergo debate among evangelical theologians (Boyd and Eddy 2002). At the end of the debate, there are just a couple of points that are verifiable. First, Christ must be one person, not two. While some have effectively argued that two minds does not equal two persons. Christ could have had two minds (one human and one divine), without meaning that he had two personalities. Somehow, both minds co-existed without creating a dual personality. Others have argued that the two natures of Christ somehow merged to create a unified mind and therefore a unified person. In light of these possible answers, what cannot be compromised is the singular personhood of Christ. Whether Christ had two minds, or one mind he absolutely must have been one person with two natures. If Christ were two persons, then he become a new being altogether. If Christ becomes a third, entirely new being, then he is not able to identify with the humanity whom he is to redeem; nor can he identify with God as the one who redeems.
So, what of the atonement and Christology? How does orthodox Christology change the way we think about atonement? Atonement, in a very general sense, changes the effects of behavior. Christ’s atonement, or expiation of sins of believers, changes the effects of sin in the lives of believers because of his dual nature. From a Christian worldview, the atonement is very personal. This is set in contrast with other religious systems (especially paganism). In other religious systems, magic is the means by which one avoids the negative effects of behavior. Sacrifice in the pagan worldview, is the appeasement of powers not persons. As Dennis Kinlaw points out, often times those powers are personified to appear as if they are personal, but in actuality, they are merely impersonal powers (Kinlaw, 2010). They are impersonal powers simply because they can be appeased through an act of magic. The effects are changed through an impersonal event (magical/mystical ceremony).
This way of thinking is set in direct opposition to the Bible’s way of understanding atonement. The atoning work of Christ is something deeply personal. What happened at Calvary is no magical event that automatically forces the divine power to change the effects of sin in the lives of people. Rather, Christ’s work on the cross is efficacious because he was the intermediary between two persons. Christ represents humanity in his humanness. Christ also represents God in his divinity. On behalf of humanity, Christ pays the penalty of sin to God. On the behalf of God, Christ offers just forgiveness and righteousness to humanity. In the cross is the reconciliation of persons. God, as a person, is able to embrace a forgiven humanity because of the person of Jesus Christ. The effectiveness of the cross is activated through the faith of the believer (rather than through singing some sort of impersonal chant or citing magical spell). Kinlaw writes:
It [sin] is not associated with some destructive power that has been unleashed and that you must magically counter or suffer its consequences. Rather, you have a God of hesed, a divine Friend who has been offended. That creates a radically different understanding of what was done and what needs to be done to correct it. Sin is now against a persona God whose character is marked by hesed…Atonement, therefore, is not a magical manipulation of demonic powers (Kinlaw 2010).
To go on to describe the personal activity of the cross, Kinlaw goes on to say, “The [sins] are not spoken away. They are removed from the back of the person who committed them to the pack of one who did not commit them” (Kinlaw, 2010). This view of atonement that is unique to the Christian tradition depends on orthodox Christology that contends for a dual nature of Jesus.
While Christology seems to be an esoteric subject, it is of the utmost importance. Even if one does has not grasped all the technical nuances behind orthodox Christology, each nuance is of critical importance. While Christological heresy can seem to split hairs over certain components that seem irrelevant to many, all Christological heresies damages the power of the gospel at its core. It is perfectly sensible that the validity of the Gospel of Jesus Christ hangs on every minute, technical nuance of understanding who Jesus Is. Jesus must be human; Jesus must be God; all in one person.
 Qoheleth is confirmed correct here; there is nothing new under the sun.