A.T. Robertson Commentary Philippians 3:6

"as touching zeal, persecuting the church; as touching the righteousness which is in the law, found blameless." — Philippians 3:6 (ASV)

As touching zeal (κατα ζηλος). So the old MSS. treating ζηλος as neuter, not masculine. He was a zealot against Christianity, "persecuting the church" (διωκων την εκκλησιαν). He was the ringleader in the persecution from the death of Stephen till his own conversion (Acts 8:1–9:9).

Found blameless (γενομενος αμεμπτος). "Having become blameless" (Galatians 1:14). He knew and practised all the rules of the rabbis. A marvellous record, scoring a hundred in Judaism.