For centuries, Scholars have debated Paul's mysterious "barb." It has been the source of much speculation, including Paul's lusts, sexual preference or physical ailments, including malaria and eye disease.
Paul, in his Galatians autobiography, identifies James as a man who replaced Peter as the head of the early Church. Additional apocryphal and secular sources assume James as heir to the church and rightfully so as his brother.
Early Christianity was a rebellious underground movement until Roman Emperor Constantine made it his religious practice in A.D. 312. These events did more for the spread of Christianity than any proselytizing efforts conducted by the Apostle Paul.