Paul claims to have been educated by Gamaliel, one of the premier teachers of the Law in the first century. Gamaliel taught between A.D. 22-55, giving us an approximate early date for Paul’s education. If Paul began study at the latest age of 16, we can guess a birth year of about 6 at the earliest. Polhill observes that several rulings of Gamaliel appear in the Mishnah, mostly having to do with marriage and divorce. Perhaps Gamiliel’s views influenced Paul’s personal comments on marriage in 1 Corinthians 7 (Polhill, Paul and his Letters, 30).
Gamaliel was himself a Pharisee in the tradition of the great Hillel. A generation before Christ there were two great rabbis, Hillel and Shammai. While this is a generalization, many of the rabbinic debates of the first century come down to the opinion of Hillel versus Shammai. With respect to Hellenism, Hillel was more open to Hellenism than Shammai and was therefore more open to cooperation with the Romans.
Evidence for this more accommodating opinion is found in the book of Acts. Gamaliel is reported to have offered somewhat lenient advice concerning the early preaching of the apostles in Acts 5:34-39. Basically, he said that if the movement is from God then it cannot be stopped, if it is not then it will not succeed. Gamaliel is reflecting the Hillel tradition of non-violence and allowing God to deal with parties that against the Jews (Polhill, Paul and His Letters, 31).
This is certainly not the opinion of his young disciple Saul when we meet him in Acts 9 and according to Paul’s own self-description. He was a ruthless persecutor who sought to stop what he saw as an aberration within Judaism. The people who Paul persecuted were diaspora Jews who accepted Jesus as Messiah and claimed that he was raised from the dead. How can we account for this violent reaction in a man trained by Gamaliel?
It is possible that Paul was not of the Hillel form of Pharasism, but rather the more radical Shammaite party. N. T. Wright describes the Shammaite Pharisee as a militant “hard-liner” that was not willing to work with Rome as long as they could study the Torah, as Hillel had said (What Saint Paul Really Said, 26). Paul was a Diaspora Jew who claimed to have been raised in a family which kept the Jewish traditions without fault. He was an ultra-conservative reacting to what he perceived as a dangerous liberal view (Jesus was the Messiah and the High Priest killed him!)