What I think we need to note about Paul was that he was one of the 12 apostles. These 12 trained the men of the church of the apostle age, the true church as the Lord gave it instructions. This church stood and grew in power even though it was an illegal church in the eyes of the world. It wasn't until Constantine made himself leader of the church, a man of the world, that the church stayed close to Christ. It marked the end f he church of the apostles.
Paul did not know Christ in the flesh as we are told the other apostles did, but we are told Paul was personally taught by Christ those three years in Arabia. Scripture also states that Paul was an apostle, not a disciple, and all apostles had to be personally taught by Christ.