Taken from an interview with John Piper  (Presented in 6 main points.  Today, point 4)

4. God is Trinity. 

And in his fullness and perfection, the Bible makes plain that, from all eternity, God has had a perfect image of himself, the radiance of his glory. The Bible calls it “the exact imprint of his nature” (Hebrews 1:3). And this image is so complete with all that God is that the Bible speaks of this image as the second person in God and uses the language of Son of God, not because there’s any biological way that he’s a son — like he had sex with Mary and had a baby; that’s not what the Bible teaches. He’s a son, the second person that has always existed in and as the perfect image of God. 

This Son is a son to indicate that they have the same nature. They’re both personal, and love reigns between them. The Bible speaks of God the Father loving God the Son, and God the Son loving God the Father, and the Bible points to the reality that this Spirit between them — this love between the Father and Son — carries, as it were, such a fullness of all that they both are that a third person exists, stands forth, has always stood forth in God. 

So, the biblical picture is that there’s one God — not three gods — and that this one God mysteriously exists as God the Father, God the Son, and God the Holy Spirit. This is one reason that it makes sense to say, as 1 John 4:8 says, “God is love.” Love has been surging from all eternity in the fellowship of the three persons of the one God. 

John Piper (@JohnPiper) is founder and teacher of desiringGod.org and chancellor of Bethlehem College & Seminary. For 33 years, he served as pastor of Bethlehem Baptist Church, Minneapolis, Minnesota. He is author of more than 50 books, including Desiring God: Meditations of a Christian Hedonist and most recently Providence.