For we are the circumcision who worship God in the Spirit, and boast in Christ Jesus, and place no trust in the flesh, though I also have confidence in the flesh.
If any other man thinks that he has reason to trust in the flesh, I have more: I was circumcised the eighth day, of the stock of Israel, of the tribe of Benjamin, and a Hebrew of Hebrews; as concerning the law, a Pharisee; concerning zeal, persecuting the church; and concerning the righteousness which is in the law, blameless.Philippians 3:3–6 — Modern English Version (Thinline Edition.; Lake Mary, FL: Passio, 2014)
Of course, the law doesn’t justify. Paul is making a proclamation of himself to be blameless according to the law. He is not making a proclamation of how he was saved, nor about his salvation. Salvation comes by way of faith, noting keeping the rudiments of the law.
Paul followed the law. He knew that keeping it meant a certain blamelessness that was available in its precepts. The law’s purpose serves as a schoolmaster. It teaches us of our need for a Redeemer. It points directly to Jesus Christ Himself, Who is the end of the law.
But what things were gain to me, I have counted these things to be loss for the sake of Christ. Yes, certainly, I count everything as loss for the excellence of the knowledge of Christ Jesus my Lord, for whom I have forfeited the loss of all things and count them as rubbish that I may gain Christ, and be found in Him, not having my own righteousness which is from the law, but that which is through faith in Christ, the righteousness which is of God on the basis of faith, to know Him, and the power of His resurrection, and the fellowship of His sufferings, being conformed to His death, if somehow I might make it to the resurrection of the dead.Philippians 3:7–11 — Modern English Version (Thinline Edition.; Lake Mary, FL: Passio, 2014)
Paul even forsook the keeping of the law and the blamelessness that comes with that for what is better in Jesus in having the righteousness from God Himself. There is no better.