The doctrine of the Trinity is the best explanation for all of the biblical evidence. There is only one God, but He exists eternally as three individual Persons and has revealed Himself as God the Father, God the Son, and God the Holy Spirit. This is different from the teaching of three individual gods because the three Persons of the Trinity are co-equal, co-eternal, interdependent, and always in complete agreement. There is one God who exists as three individual Persons. Thus, the Father is God, the Son is God, and the Holy Spirit is God; however, the Father is not the same person as the Son, nor is the Son the same person as the Holy Spirit. This is sometimes complicated by the fact that God the Father is often simply called “God” in the New Testament.
The first three verses of the Gospel of John give us an idea of how this works out:
John 1:1. In the beginning was the Word . . . (We know from verse 14 that the Word is Jesus. In the beginning, He was already there.)
. . . and the Word was with God . . . (At least two Persons are in view here: one called “God” and one called “the Word.”)
. . . and the Word was God (The Word is distinct from God, yet He is also called “God.” The Word is divine in His essential nature.)
John 1:2. He was with God in the beginning (After the essential identification of the Word as God, once again the distinction is emphasized—He was with God when it all began.)
John 1:3. Through him all things were made; without him nothing was made that has been made (Here, we see that the Word is actually the Creator. He made everything. In the Old Testament, we are told that God created everything--Genesis 1:1.)
It is this kind of biblical information that led to the formulation of the doctrine of the Trinity. When “God” is spoken of in the Old Testament, most people probably think of God the Father, but it would be more accurate to think of “God the Trinity.” In the New Testament, we see how each Person of the Trinity assumed different roles in the redemption of lost humanity, but the different Persons are always in complete agreement, acting as one.
Jesus is God, but Jesus (who is God the Son) is not the same Person as God the Father or God the Holy Spirit.