Peter and Paul were both Apostles chosen by God. One to lead the Israel and one to lead the Body of Christ. One to go to circumcision and one to go to the uncircumcision. One to teach the kingdom principles and the other to teach heavenly grace. Who were to only two in the Bible who gave instructions to follow them? Reminder, no doctrine can be found in the book of Acts. It is a God inspired transitional history book where God shifts from Israel to the Gentiles.