I started Alan Segal's Paul the Convert. There were two interesting items in my reading so far. First, Segal attempts to demonstrate that Paul indeed was a convert, against thinkers such as Krister Stendahl who maintain that Paul merely saw himself as one who was called to be a missionary to the Gentiles, not as a convert from one religion to another. According to Segal, Paul contrasts his life then and his life now as well as talks about his transformation, and that fits our understanding of conversion. While Segal acknowledges that Paul did not say that he repented----when repentance, according to Judaism and Christianity, was a key ingredient of conversion----Segal says that Paul was a convert according to definitions today, not necessarily according to how conversion was conceptualized in Paul's day. (UPDATE: I may be misunderstanding Segal here, for he later appears to argue that Paul was a convert according to ancient standards.) Segal says that Paul leaves out repentance, in part, on the basis of Paul's statement in Philippians 3 that he was blameless in his observance of the law before he came to Christ. But, in my opinion, repentance and transformation are similar, and Paul did believe that where he was as a Christian was better than where he was as a Pharisee.
Second, Segal talks about the belief in Second Temple and subsequent Judaism (albeit not rabbinic Judaism) that God has exalted certain human beings (i.e., Enoch, Moses) to a status of heavenly ruler, and sometimes has even given them his own name. I've asked before why the early Christians believed that Jesus had a divine sort of status. Did Jesus claim that for himself? Maybe Jesus did not, but his followers believed that he was a special and a righteous man and applied to him what others applied to Enoch and others: they said that God exalted Jesus to become a heavenly ruler. I don't know.