Further, my brothers and sisters, rejoice in the Lord! It is no trouble for me to write the same things to you again, and it is a safeguard for you. Watch out for those dogs, those evildoers, those mutilators of the flesh. For it is we who are the circumcision, we who serve God by his Spirit, who boast in Christ Jesus, and who put no confidence in the flesh— though I myself have reasons for such confidence.
Chapter 3 starts out with Paul urging the people to rejoice in the Lord, and that seems simple enough, but then the subject seems to turn. What follows is a denunciation of those who would teach the Philippians that they must first become Jews before they can be saved.
The word that jumps out at me in the second verse is the word “dogs”. So catch this spectacle: Paul the Jew is calling those Jews who insist that a Gentile been circumcised a Jew before they can become a Christian, “dogs”. That is amazing when you consider that “dogs” are what the Jews call Gentiles! Dogs, evil doers and mutilators of the flesh; hey Paul, tell us how your really feel! As we saw in Paul’s letter to the Galatians, he has no patience with this teaching, and there is little wonder why; the old ways are entirely over and done.
In verse 3, he points out who are the “circumcision”, the ones who serve in the Spirit and boast in Christ; and it isn’t the Jews. Again, the old ways are done, gone, and irrelevant. We as Christians have “no confidence” in the flesh, not even Paul, who might have a reason to claim some confidence in the flesh. This is an interesting little situation, for Paul has been writing from the end of the first chapter, and all through the second about being “worthy of the gospel” and through all that he described how we should be imitators of Christ, which is the sign of the New Covenant. Circumcision was the sign of a different covenant, and was required of Abraham and his descendants. All of those old ways were merely illustrations of the reality to come in Christ, and now that the reality has come, those old physical things are over. Thus, Paul dismisses confidence in the flesh (circumcision).