Is the Trinity revealed in the Old Testament or only in the New?
The Trinity is revealed in the New Testament, especially through Paul, who unveils it as part of the mystery. The Old Testament contains evidences of the triune God but remains vague; the Hebrews and rabbis did not recognize the Trinity there. The full revelation that God is Father, Son, and Holy Spirit comes in the New.
Les explains that the Old Testament is vague about the Trinity, though it does contain evidences of the triune God. He points out that Hebrews and rabbis, even today, accuse Christians of being almost pagan because they think Christians worship three gods; they do not recognize the Trinity in the Old Testament. Les teaches that the revelation of God as Father, Son, and Holy Spirit is part of the mystery Paul brings out in the New Testament, as seen in Colossians and 1 Corinthians 15. This mystery includes Gentiles becoming one with God and God revealing who He really is as the triune God.