Both the Nicene and Chalcedonian Creeds affirm that Jesus came down from heaven and took to Himself a human nature “for us and for our salvation.” The reason for this act, also known as the Incarnation, was that Jesus could reconcile us to God by His life, death, and resurrection on our behalf. For this reason, the doctrine of the Incarnation is inseparable from the doctrine of atonement.
Atonement is a theological term for people being “at one with” God. In the Old Testament, the sacrifices of the Mosaic Covenant anticipated the full atonement made possible through the person and work of Jesus Christ. Atonement with God requires the presentation of a perfect offering (Ex. 30:10; Lev. 17:11). But after the Fall, humanity suffers from sin and death, making it impossible for us to atone for our sins ourselves.
Jesus did away with sin by the sacrifice of Himself (Heb. 9:26). His life of perfect obedience, His suffering and death on the Cross, His resurrection from the dead, and His presentation of Himself in heaven have made possible our atonement with God (John 1:29; Heb. 7:27).
Because Jesus is both divine and sinless, He possesses the righteousness that our sin deprives us of. Because He became truly human, He was able to take our place. His death is described as a “ransom” in Mark 10:45. This language expresses the ideas of both payment and rescue. Jesus’ death is the only payment that God will accept for our sins. Because Jesus was resurrected and ascended into the presence of God and presented Himself to the Father, it is possible for us to be restored to a right relationship with God (Heb. 9:11–14).
Without atonement, we can never have forgiveness. Christ’s sacrifice of Himself on our behalf is the reason that God can offer forgiveness as a free gift to all who receive it by faith. The fact that we have been forgiven is the reason we are able to forgive those who have sinned against us. Without Christ, true forgiveness in either sense would be beyond our reach. The doctrine of atonement should also inspire us to devotion. Those who know that they have been forgiven much by God will love the God who forgave them much (Luke 7:47).
To learn more, read Atonement: A Guide for the Perplexed by Adam J. Johnson (T&T Clark).