Matthew 23:15 – "Woe to you scribes and Pharisees, hypocrites, because you travel about on sea and land to make one proselyte; and when he becomes one, you make him twice as much a son of hell as yourselves."
I Corinthians 11:1 – "Be imitators of me, just as I also am of Christ."
Acts 23:6 – "But perceiving that one part were Sadducees and the other Pharisees, Paul began crying out in the Council, 'Brethren, I am a Pharisee, a son of Pharisees; I am on trial for the hope and resurrection of the dead."
Some of the critics at times try to prove from these two scriptures that the Apostle Paul, even though he is considered to have been the major force in spreading early christianity with his missionary work, traveling the Roman Empire, was not really even a "Christian".
They take Jesus' words about "Pharisees" and then consider the passage in Acts 23 (where Paul spoke of being a Pharisee) in light of that, coming to the conclusion that these verses are contradictory and actually Paul must have been a liar claiming that he was an imitator of Christ. Now, the question is, did Paul here claim to be a Pharisee rather than a Christian? Was he then counting himself to be one of those hypocrites Jesus had spoken of?
Verse 6 already has an answer, for it states "I am a Pharisee, A SON OF Pharisees …" Paul was making reference to his past as a Jew, that he had grown up as a son of a Pharisee, that he at one time had been part of the group of the Pharisees ... prior to the experienced conversion at Damascus. Also, the Jews now interrogating him certainly didn't understand him to claim that he was still a Pharisee, else why did they continue persecuting him? According to Philippians 3:5-7, Paul made clear that he had been a Pharisee, as concerning the understanding of the Law, but that now for Christ he had counted everything else from before nothing but loss.
The apparent contradiction is solved quickly by considering the immediate context of Acts 23, and by taking into account the broader picture of Paul's life. Yes, he had been a Pharisee at one time, but now he was an imitator of Christ, a Christian, to whom all the former achievements meant nothing compared with the knowledge of Jesus Christ.