Colossians 2:11: In Him you were also circumcised with a circumcision made without hands, in the removal of the body of the flesh by the circumcision of Christ.
You are circumcised, Paul says. You, Gentile Christians, who have been buried with Jesus in baptism, you are true Jews because by baptism you receive the circumcision of Christ.
Christian circumcision strips off the body of flesh. For Paul, “flesh” refers to ancestry, the privileges of birth, culture, and race. Jews boasted they were the seed of Abraham, Greeks were proud of being civilized, not like those stinky barbarians. We Americans believe our civilization is the best the world has ever seen.
The circumcision of Christ strips away all fleshly pride and leaves us with one common identity. You are who you are in the body of Christ, not in the body of flesh. If we boast, we boast in Him.
In Israel, only the circumcised could eat the Passover meal. Having become Jews by the circumcision of Christ, we keep a new and better Passover, for Christ our Passover has been sacrificed for us.