Faith in the deity of Christ is necessary to being a Christian. It is an essential part of the New Testament gospel of Christ. Yet in every century the church has been forced to deal with people who claim to be Christians while denying or distorting the deity of Christ.
In church history there have been four centuries in which confession of the deity of Christ has been a crucial and stormy issue inside the church. Those centuries have been the fourth, fifth, nineteenth, and twentieth. Since we are living in one of the centuries where heresy assaults the church, it is urgent that we safeguard the church's confession of Christ's deity.
At the Council of Nicea in A.D. 325, the church, in opposition to the Arian heresy, declared that Jesus is begotten, not made, and that His divine nature is of the same essence (homo ousios) with the Father. This affirmation declared that the Second Person of the Trinity is one in essence with God the Father. That is, the "being" of Christ is the being of God. He is not merely similar to Deity, but He is Deity.
The confession of the deity of Christ is drawn from the manifold witness of the New Testament. As the Logos Incarnate, Christ is revealed as being not only preexistent to creation, but eternal. He is said to be in the beginning with God and also that He is God (John 1:1-3). That He is with God demands a personal distinction within the Godhead. That He is God demands inclusion in the Godhead.
Elsewhere, the New Testament ascribes terms and titles to Jesus that are clearly titles of deity. God bestows the preeminent divine title of Lord upon Him (Philippians 2:9-11). As the Son of Man, Jesus claims to be Lord of the Sabbath (Mark 2:28) and to have authority to forgive sins (Mark 2:1-12). He is called the "Lord of glory" (James 2:1) and willingly receives worship, as when Thomas confesses, "My Lord and my God!" (John 20:28).
Paul declares that the fullness of the Godhead dwells in Christ bodily (Colossians 1:19) and that Jesus is higher than angels, a theme reiterated in the book of Hebrews. To worship an angel or any other creature, no matter how exalted, is to violate the biblical prohibition against idolatry. The I ams of John's Gospel also bear witness to the identification of Christ with Deity.
In the fifth century, the Council of Chalcedon (A.D. 451) affirmed that Jesus was truly man and truly God. Jesus' two natures, human and divine, were said to be without mixture, confusion, separation, or division.