Question: where in the bible do they talk about the holy 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 ...