Question: where does it say in the bible about the trinity?
Answer: While the developed doctrine of the Trinity is not explicit in the books that constitute the New Testament, the New Testament possesses a "triadic" understanding of God and contains a number of Trinitarian formulas, including Matthew 28:19, 2 Corinthians 13:14, 1 Corinthians 12:4-5, Ephesians 4:4-6, 1 Peter 1:2 and ...