Romans 4:10

4:10 How then was it credited to him? Was he circumcised at the time, or not? No, he was not circumcised but uncircumcised!

Romans 2:25

2:25 For circumcision ¹  has its value if you practice the law, but ²  if you break the law, ³  your circumcision has become uncircumcision.

Romans 4:12

4:12 And he is also the father of the circumcised, ⁴  who are not only circumcised, but who also walk in the footsteps of the faith that our father Abraham possessed when he was still uncircumcised. ⁵ 

[2:25]  ¹ sn Circumcision refers to male circumcision as prescribed in the OT, which was given as a covenant to Abraham in Gen 17:10-14. Its importance for Judaism can hardly be overstated: According to J. D. G. Dunn (Romans [WBC], 1:120) it was the “single clearest distinguishing feature of the covenant people.” J. Marcus has suggested that the terms used for circumcision (περιτομή, peritomh) and uncircumcision (ἀκροβυστία, akrobustia) were probably derogatory slogans used by Jews and Gentiles to describe their opponents (“The Circumcision and the Uncircumcision in Rome,” NTS 35 [1989]: 77-80).

[2:25]  ² tn This contrast is clearer and stronger in Greek than can be easily expressed in English.

[2:25]  ³ tn Grk “if you should be a transgressor of the law.”

[4:12]  ¹ tn Grk “the father of circumcision.”

[4:12]  ² tn Grk “the ‘in-uncircumcision faith’ of our father Abraham.”