Paul was very zealous for Judaism.
Gal 1:14
I was advancing in Judaism beyond many Jews of my own age and was extremely zealous for the traditions of my fathers.
Also remember what we read in Phil 3:5 where Paul expounds on being a Pharisee and Hebrew of Hebrews.
Paul used his strict Pharisaical background.
Acts 23:6
Then Paul, knowing that some of them were Sadducees and the others Pharisees, called out in the Sanhedrin, "My brothers, I am a Pharisee, the son of a Pharisee. I stand on trial because of my hope in the resurrection of the dead."
We read in Acts 22:3 that Paul trained under Gamaliel, but who was Gamaliel?
Acts 5:34
But a Pharisee named Gamaliel, a teacher of the law, who was honored by all the people, stood up in the Sanhedrin and ordered that the men be put outside for a little while.
We know that he had a sister in Jerusalem when the Jews plotted to kill him.
Acts 23:16
But when the son of Paul's sister heard of this plot, he went into the barracks and told Paul.
Paul may have been married.
1 Cor 9:1-6 The rights of an apostle.
Am I not free? Am I not an apostle? Have I not seen Jesus our Lord? Are you not the result of my work in the Lord? {2} Even though I may not be an apostle to others, surely I am to you! For you are the seal of my apostleship in the Lord. {3} This is my defense to those who sit in judgment on me. {4} Don't we have the right to food and drink? {5} Don't we have the right to take a believing wife along with us, as do the other apostles and the Lord's brothers and Cephas ? {6} Or is it only I and Barnabas who must work for a living?
Paul was a member of the Jewish council.
Acts 2 ...