2Listen! I, Paul, am telling you that if you let yourselves be circumcised, Christ will be of no benefit to you. 3Once again I testify to every man who lets himself be circumcised that he is obliged to obey the entire law. 4You who want to be justified by the law have cut yourselves off from Christ; you have fallen away from grace. 5For through the Spirit, by faith, we eagerly wait for the hope of righteousness. 6For in Christ Jesus neither circumcision nor uncircumcision counts for anything; the only thing that counts is faith working through love. (Galatians 5:2-6, NRSV)
Here is the thing Paul is saying, if you allow yourself to be circumcised when you were not as a part of the covenant at 8 days old, then it doesn’t do you any good and actually does harm to the mission. You see the last sentence says it all, neither circumcision nor uncircumcision means anything. Neither of these options saves you.
It is Christ that saves us and no outward sign. When we do things for others we show that there are things that are necessary for salvation and that simply isn’t true. There is nothing we can do to make us right with God. Jesus does it all.
Trust in the promise and hold tight and do not let others convince you otherwise.