Who was Saul of Tarsus and how did he treat those who opposed the Jewish religion?

Les teaches that Saul of Tarsus was a Pharisee of the Pharisees and was corrupt in the religion. He explains that Saul had no mercy for those who opposed the Jewish religion, so he could drag them in, throw them into dungeons, or commit them to stoning. Les notes that this is Saul's own account: he said, "You have heard of my manner of living, I profited in the Jews religion." Les also points out that Scripture generally uses the word religion in a bad light, with perhaps James as an exception when he says the religious person will bridle his tongue. Here, Paul says he profited in the Jews' religion because it was a bad, corrupt system. Les connects this to Jesus' account with the Pharisees, who were corrupt, and to the incident when one of them struck Paul on the face and Paul called him a whited sepulcher, later taking it back because he did not know he was the high priest.