What does Philippians 3:6 mean?

For we are the circumcision, who worship God in the Spirit, and rejoice in Christ Jesus, and have no confidence in the flesh;

though I myself might have confidence even in the flesh. If any other man thinks that he has confidence in the flesh, I yet more:

circumcised the eighth day, of the stock of Israel, of the tribe of Benjamin, a Hebrew of Hebrews; concerning the law, a Pharisee;

However, I consider those things that were gain to me as a loss for Christ.

Yes most certainly, and I count all things to be a loss for the excellency of the knowledge of Christ Jesus, my Lord, for whom I suffered the loss of all things, and count them nothing but refuse, that I may gain Christ

and be found in him, not having a righteousness of my own, that which is of the law, but that which is through faith in Christ, the righteousness which is from God by faith;