1. Through him and for his name's sake, we received grace and apostleship to call people from among all the Gentiles to the obedience that comes from faith.Paul's letters were seen by the apostle to the Jews, Peter, as being scripture, the distortion of which in both cases leads to spiritual destruction:
2. I am talking to you Gentiles. Inasmuch as I am the apostle to the Gentiles, I make much of my ministry
3. For God, who was at work in the ministry of Peter as an apostle to the Jews, was also at work in my ministry as an apostle to the Gentiles.
4. And for this purpose I was appointed a herald and an apostle—I am telling the truth, I am not lying—and a teacher of the true faith to the Gentiles.
Bear in mind that our Lord's patience means salvation, just as our dear brother Paul also wrote you with the wisdom that God gave him. He writes the same way in all his letters, speaking in them of these matters. His letters contain some things that are hard to understand, which ignorant and unstable people distort, as they do the other Scriptures, to their own destruction.
like referring to him as loony?
As we look at the Scriptures we see the primary doctrinal writings were the work of Paul.. I believe that he selected to write the majority of the NT ..
Paul was the apostle and teacher of the true faith to the Gentiles as opposed to being an apostle to the Jews. The NT church quickly became composed primarily of Gentile believers; therefore, the major part of the NT church fell under the teaching authority of the one appointed by God to be a teacher and apostle to the Gentiles
Remember that Paul spent much of his initial years as Apostle among the Jews and that he preached all things to all men. His earlier efforts were in the synagogues and he was present during the movement from Christianity as Jewish sect to the separation of Christianity from Judaism. If you follow through Acts, for instance, we see several instances where he went deliberately and provoked the Jews on their own turf, as it were.
As odd as it may sound, Peter converted the first Gentile of all the Apostles in Acts 10. Thomas left the Middle East and wound up converting portions of the west coast of India. So Paul was not the one and only evangelist to the Gentiles.
But there is no question that Peter accepted Paul after some initial hesitation - Paul is the one with the chip on his shoulder and keeps protesting throughout his writings about being accepted by the others.