Neither circumcision nor uncircumcision counts for anything, but only faith working through love. Paul in today’s reading wants to remind his hearers of the freedom into which they were evangelized. Christ, in his death and resurrection, has set humanity free: freedom to attain full self-transcendence. It is a freedom that had been inhibited by the existence of “material” laws. Such laws, while in themselves not malicious, became obstacles on humanity’s way to the self-transcendence (the self-transcendence such as that found in Jesus Christ). Paul reminds the Galatians that customs like circumcision end up enslaving its adherents instead of setting them on the path to self-transcendence (for once you get yourself circumcised, you are bound to observe to all the other laws and by-laws that are attached to circumcision).
Having himself been part of a system that fronted observance to laws and traditions, Paul knew all too well how such a path end up being exclusive and discriminatory rather than inclusive and tolerant. Paul was aware of how he had used the practice to look down upon those who were unlike him (the uncircumcised). The freedom that Jesus brings does away with such obstacles.