Paul admitted that he arrested and persecuted Christians. This was work of the Sadducces, not the Pharisees. How do you explain that contradiction?
They were both part of the group known as "teachers of the Law", religious leaders in Jesus' day. Although they disagreed on some major doctrines like the resurrection of the dead, they quite often teamed up on the early Christians. They came together against John the Baptist as told in Matthew 3:7
But when he saw many of the Pharisees and Sadducees come to his baptism, he said unto them, O generation of vipers, who hath warned you to flee from the wrath to come?
They also came against Jesus many times as told in Matthew 16:1
The Pharisees also with the Sadducees came, and tempting desired him that he would shew them a sign from heaven.
And in Matthew 26 it sounds like they all got together to get him:
3Then assembled together the chief priests, and the scribes, and the elders of the people, unto the palace of the high priest, who was called Caiaphas,
4And consulted that they might take Jesus by subtilty, and kill him.
So, NL, I don't see the big deal about Paul being a Pharisee. Why do you?