Well, I think you might consider what Paul actually wrote about Jesus. Yes, he talks about Jesus' importance, and the importance of his death and resurrection. But what else? What does Paul mention that the Gospels were so concerned with? What would we know about Jesus if Paul's were the only texts to survive? Next to nothing!
Paul says nothing about Jesus’ birth or parents or early life, nor his baptism, temptation in the wilderness, teaching about the coming Kingdom of God. Paul never mentions that Jesus ever told a parable, healed anybody, cast out a demon, or raised the dead. Paul seems to have been unaware of the Transfiguration, triumphal entry into Jerusalem, cleansing of the Temple, interrogation by the Sanhedrin or trial before Pilate, rejection in favor of Barabbas, of his being mocked, of his being flogged, etc. etc. etc. Wow!
My own feeling is that Paul, as very much a Hellenistic Jew, was channeling a great deal of the prevailing "mystery religions" of the time, and settled on a character who he never met, never heard speak, never read a word written about him, and whose followers he was for a time persecuting. And in so doing, basically founded a new religion.
As to writing "under inspiration," I can find you texts of so many, many writers who claimed to be inspired by God -- and whose writings you would reject in a heartbeat. How do you come to believe Paul's "inspiration" and not Muhammed's? Your own religious predisposition, of course. But how would you and the Muslim go about convincing a visitor from another world which "inspiration" was actually "from God.?" How would either of you convince me?