Part 1 is available here, Part 2 here, Part 3 here, Part 4 here, Part 5 here, and Part 6 here.
KRT: What do we know about the relationship of Peter and Paul?
AP: We know some things, but we have to be quite imaginative. We believe that the relationship between Peter and Paul was better than the relationship between James and Paul. In Acts, Peter organizes the mission to the Gentiles, and Paul follows in that work. From that we can conclude that the author of said text, who we call Luke, wanted to present him as a man who was not as stubborn as some former Essenes and former Pharisees of Jerusalem that converted to Judeo-Christianity and required people to become Jews in order to be saved.
I think Peter stood in the middle between these two positions–the Judaizing James, the "brother of the Lord," and the Hellenized Paul of Tarsus, who allowed Jews remain as they were and Gentiles the same. In other words, Jews kept living like Jews with faith in Jesus, and Gentiles did not absorb all of the requirements of the law . . . . They remained Gentiles, and did not become Jews. In Galatians 2 we see that Peter and Paul are angry at each other. Paul blamed Peter for refusing the eat with the Gentiles now that some visitors from Jerusalem had come to where they were. He started acting like a strict Jew, like he didn't even know any of the Gentiles.
To reconstruct who Peter is, well, is difficult. The first letter attributed to him has a lot of Paul's theology. And the second was not written by him. To reconstruct Peter's theology we have to rely on Acts and the Gospels, as well as the Pseudo-Clementine Homilies.
Paul and James, however, had to keep their distance, but each with mutual respect for the other. Paul appears in his letters raising money for the Jerusalem Christians, who were led by James. They had sold their possessions because they expected the imminent end of the world and were literally "starving" as they say at the beginning of Acts. Paul had hoped to win them over through this, but he failed; the Jews, along with the Romans, arrested him right there in Jerusalem. The Christians themselves were probably the ones who permitted all of this to take place, and he was brought before the Roman procurator. As we know, Paul was eventually beheaded in Rome.