St Paul did not invent Christianity nor did he invent the divinity of Christ:
Jesus: Thomas answered him, "My Lord and my G-d!" Jesus said to him, "Have you believed because you have seen me? Blessed are those who have not seen and yet have come to believe". (John 20:28-29)
Paul: From them, according to the flesh, comes the Messiah, who is over all, G-d blessed forever. (Romans 9:5)
JESUS: You call me Teacher and Lord - and you are right, for that is what I am. (John 13:13)
PAUL: There is... one Lord, Jesus Christ. (1 Corinthians 8:6)
JESUS: All of them asked, "Are you, then, the Son of G-d?" He said to them, "You say that I am". Then they said, "What further testimony do we need? We have heard it ourselves from his own lips!" (Luke 22:70-71)
PAUL: Immediately he began to proclaim Jesus in the synagogues, saying, "He is the Son of G-d". (Acts 9:20)
JESUS: I am the Alpha and the Omega, the first and the last, the beginning and the end. (Revelation 22:13)
PAUL: He is the beginning. (Colossians 1:18)
JESUS: G-d did not send the Son into the world to condemn the world, but in order that the world might be saved through him. (John 3:17)
PAUL: The saying is sure and worthy of full acceptance, that Christ Jesus came into the world to save sinners. (1 Timothy 1:15)
JESUS: I am the way, and the truth, and the life. (John 14:6)
PAUL: Surely you have heard about him and were taught in him, as truth is in Jesus. (Ephesians 4:21)
I don't believe that the early church was invented by St. Paul either. The Church existed long before the rest of the apostles accepted Paul as an apostle( Acts 9:1-31; 15:1-35; Galatians 1:11-24, 2:1-10; 2 Peter 3:15-16). The disciples were preaching Christ long before St Paul arrived on the scene.
The Johanne school believed in the Trinity. Polycarp says in his epistle "we also ought to forgive: for we are before the eyes of our Lord and G-d, and we must all stand at the judgment-seat of Christ"(6:2). Iranaeus says in Against Heresies "G-d, then, was made man, and the Lord did Himself save us, giving us the token of the Virgin"(3:21:1) and that "the Son, eternally co-existing with the Father, from of old, yea, from the beginning, always reveals the Father to Angels, Archangels, Powers, Virtues..."(2:30:9). Hippolytus says in Against The Heresy Of One Noetus "As far as regards the power, therefore, G-d is one. But as far as regards the economy there is a threefold manifestation, as shall be proved afterwards when we give account of the true doctrine"( 8 ). These three figures carry great apostolic authority since Hippolytus was a student of Iranaeus, who was a student of Polycarp, who was a student of St John, who was a student of Jesus. Yet all of them clearly believed in the divinity of Christ.