Why did Paul constantly have to defend his apostleship?
Many, even among conservative Christianity, refused to give Paul the time of day, so he had to defend his apostleship. He was uniquely the apostle of the Gentiles, not one of the twelve, and magnified his office, guaranteeing his message came from the Ascended Lord.
Les explains that throughout Paul's epistles he constantly had to defend his apostleship, and if Paul were alive today he would still be doing it. The reason is that many, even among rather conservative Christianity, won't give Paul the time of day and are remiss in treating him that way. Paul's defense rests on his unique commission: in Romans 11 he writes to Gentiles, 'I am the apostle of the Gentiles,' not sharing that apostleship with anyone else. He was not one of the twelve, because they went to Israel. He magnified his office and, as he defends his apostleship in Galatians, says 'I lie not,' guaranteeing that what he says came from the Ascended Lord.