There is only one God, but the Trinity refers to the three persons in the Godhead—the Father, the Son (Jesus) and the Holy Spirit. Each One is wholly God—not just a part of God. And together, they are God in oneness. (See Matthew 28:19.)
Each Person of the Trinity has individual characteristics, yet none ever acts independently or in opposition to the others. There is always total unity and harmony. “For there are three that bear record in heaven, the Father, the Word (the Son), and the Holy Ghost: and these three are one” (1 John 5:7-8).
The word Trinity itself is not found in the Bible. But the concept of the Trinity can be found from the beginning, in the book of Genesis. In the account of Creation, God said, “Let us make man in OUR image, after OUR likeness...” (Genesis 1:26, KJV).
Another characteristic of the Trinity is order. It is not an order of importance, but an order of operation. All plans come from the Father, through the Son, by the Holy Spirit. The Father initiates, the Son proclaims (He is the Word in John 1), and the Holy Spirit executes. Each activity is vital but incomplete without the others.
An example of the Trinity working together in harmony is found in Matthew 3:16-17: “After his baptism, as Jesus came up out of the water, the heavens were opened and he saw the Spirit of God descending like a dove and settling on him. And a voice from heaven said, 'This is my dearly loved Son, who brings me great joy.'”