Galatians 5:2 Behold, I Paul say unto you, that if ye be circumcised, Christ shall profit you nothing.
One of a few times Paul references His Name, and this to bring importance to the matter. He Paul and apostle commissioned by Christ and accepted by the original Apostles, all were chosen by Christ. So Paul is sort of putting Himself up as collateral to add weight to this matter. He is not speaking to the past practice of circumcision, but the prompting from some of the Jewish leaders for gentiles to get circumcised. The gentiles were easy targets, the Jews had hundreds of years religion and laws and ceremony to throw at the gentile that they were not to fond of. I hired into GM Truck& Bus in 1973 in 1979 I was saved, as soon as I started carrying a bible to work I was attacked, not by pagans but by charismatic zealots, who insisted I had to speak in tongues to prove I was saved. This is no different in Paul’s day Gentiles receiving Christ and immediately they were attacked by Jewish zealots you have to be circumcised to prove you are saved. Now I by God grace had enough wisdom to refute these claims. and it also drove me deeper into the word of God. Now these Gentiles did not have the word of God available to them this is where Paul is so important, He was there only life support to the will of God. He was their only source of truth. It was an awesome responsibility but where God guides He also provides. We can rest assured that he whom He did predestination, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified. So not even the Jewish zealots can stay the will of God. (Romans 8:30)