The Meaning of the Trinity
Each of the persons of the Trinity is fully God. God the Father’s deity is shown from the first verse of the Bible — “In the beginning, God created the heavens and the earth” (Gen. 1:1) — and throughout the pages of Scripture. When the Bible refers simply to God, more often than not it is referring to God the Father.
But God the Son, who came to earth as Jesus Christ, is also fully God. As Paul writes of Jesus in Colossians 2:9, “In him the whole fullness of deity dwells bodily.” Therefore, Jesus’ disciple Thomas was correct when he said to Jesus, “My Lord and my God!” (John 20:28).
In fact, John said he wrote his gospel so that people would “believe that Jesus is the Christ, the Son of God” (John 20:31).
Finally, God the Holy Spirit is also fully God. Because both the Father and Son are God, it makes sense that all three are mentioned with equal importance in passages like Matthew 28:19 (“baptizing them in the name of the Father and of the Son and of the Holy Spirit”). This indicates that the Scripture views all three as fully God. Peter confirms this view when he accuses someone of lying “to the Holy Spirit” (Acts 5:3) and then further explains that this man has “not lied to men but to God” (Acts 5:4). The Spirit, Paul says, is omniscient like God the Father when he writes, “No one comprehends the thoughts of God except the Spirit of God” (1 Cor. 2:11).
But the Bible is also clear that there is only one God and not three. The Bible says that God is only one essence or one being. Deuteronomy 6:4 says, “The LORD is one.” God frequently echoes this statement when he speaks, making it clear that there is no other God but him. Isaiah 45:5 is one example of this: “I am the LORD, and there is no other, besides me there is no God.”
Paul affirms this in Romans 3:30 when he writes, “God is one” and again in 1 Timothy 2:5 when he writes, “There is one God.” In James 2:19 we find that even the demons acknowledge this: “You believe that God is one; you do well. Even the demons believe — and shudder!”