The Christian position on circumcision was prophesied by Jeremiah. It's not just Pauline. The entire apostolic church was united in their perspective, and from near the earliest.
Jeremiah 9:25-26: “Behold, the days are coming,” declares the Lord, “that I will punish all who are circumcised and yet uncircumcised— Egypt and Judah, and Edom and the sons of Ammon, and Moab and all those inhabiting the desert who clip the hair on their temples; for all the nations are uncircumcised, and all the house of Israel are uncircumcised of heart.”
Paul echoes these sentiments in the end of Romans 2. He couples the label of "Jew" to those of the circumcision of the heart. John, in his Apocalypse, records Jesus expanding on Paul's conceptual understanding here, speaking of people who claim to be Jews and are not, but do lie: the Synagogue of Satan (2:9, 3:9). Hm, I wonder who this could be?
Peter affirms the lack of requirement for circumcision in Acts 15.
Circumcision's lack of value is all through Paul's work. Plainest, he declares in Titus 1:10-11: For there are many unruly and vain talkers and deceivers, specially they of the circumcision: Whose mouths must be stopped, who subvert whole houses, teaching things which they ought not, for filthy lucre's sake.
Who was he talking about here? Maybe that "Synagogue of Satan" who claim to be Jews?