Quotes about circumcision from throughout Christian History.
But as to their meticulousness concerning foods, their superstition regarding the Sabbaths, their boasting about circumcision, and their fancies about fasting and the new moons—which are utterly ridiculous and unworthy of notice—I do not think you need to learn anything from me. For … to glory in the circumcision of the flesh as a proof of election, as if on account of it they were especially beloved by God, how is it not a matter of ridicule? (ch. 4)
Is there any other matter, my friends, in which we [Christians] are blamed [by the Jews] than this: that we do not live according to the Law, are not circumcised in the flesh as your forefathers were, and do not observe Sabbaths as you do? (Dialogue with Trypho, a Jew 10)
[Trypho, the Jew, speaking] This is what are most at a loss about. You [Christians], professing yourselves to be godly and supposing yourselves better than others, are not separated from them. You do not alter your way of living from that of the nations in that you observe no festivals or Sabbaths and do not have the right of circumcision. (Dialogue with Trypho, a Jew 10)
The command of circumcision … was a type of the true circumcision, by which we are circumcised from deceit and iniquity through him who rose from the dead on the first day after the Sabbath. (Dialogue with Trypho 41)