Galatians 5:2, 6, 11

Behold I, Paul, say to you that if you receive circumcision, Christ will be of no benefit to you.

For in Christ Jesus neither circumcision nor uncircumcision means anything, but faith working through love.

But I, brethren, if I still preach circumcision, why am I still persecuted? Then the stumbling block of the cross has been abolished.