Paul turns the statement of Romans 2:25 around. If a circumcised lawbreaker loses the benefit of circumcision, what about an uncircumcised Gentile who keeps what the law requires? The question expects a yes. Barnes gives the sense: "shall he not as certainly and as readily be accepted by God as if he were a Jew?" Paul's aim is to show that the outward sign alone does not make anyone right with God. As Barnes says on the verse before, "The mere sign can be of no value."

Paul answers in Romans 2:27-29. The Gentile who fulfils the law will "judge thee" who transgress it (Romans 2:27). Then he defines the true Jew: "he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God" (Romans 2:29). The question raises its own objection, which Paul takes up next: "What advantage then hath the Jew?" (Romans 3:1).

Circumcision was the covenant sign given to Abraham; Stephen calls it "the covenant of circumcision" (Acts 7:8), a verse Barnes cites on Romans 2:25. Here "the uncircumcision" means uncircumcised people. Gill, on the next verse, says, "That is, the Gentiles, who are by nature uncircumcised."

Both commentators treat the "if" as a supposed case. Barnes says, "The apostle does not expressly affirm that this was ever done; but he supposes the case," to show the principle. Gill agrees that "These words are spoken hypothetically," and says they can only be fully true of those who "from a principle of grace" obey the law, looking to Christ for righteousness. The verb "counted" is logizomai, to reckon. Paul uses the same verb in Romans 4:3: Abraham "believed God, and it was counted unto him for righteousness."

God looks at the heart. The Old Testament itself called for this: "Circumcise therefore the foreskin of your heart" (Deuteronomy 10:16), and promised, "the LORD thy God will circumcise thine heart" (Deuteronomy 30:6). Barnes cites both on Romans 2:28-29. Paul is not inventing a new idea. He is recovering what the law had said all along.

Later in the letter Paul shows how God does this. Abraham "received the sign of circumcision, a seal of the righteousness of the faith which he had yet being uncircumcised: that he might be the father of all them that believe, though they be not circumcised" (Romans 4:11). Matthew Henry applies Romans 2:28-29 to Christians too: "He is not a Christian that is one outwardly, nor is that baptism which is outward in the flesh."