“So, if a man who is uncircumcised keeps the precepts of the law, will not his uncircumcision be regarded as circumcision?” -Romans 2:26
In this and the following verses, Paul unpacks the logic for his case. We should not suppose there is a particular occasion Paul has in mind but a theoretical case in which he demonstrates the value of keeping the Law with the value of the physical sign all by itself.
The simple point of Paul’s argument is that the honest keeping of the Law is superior to circumcision, which is an outward sign of this inward commitment, and therefore subordinate to the Law. Circumcision was made as a sign for those committed to the keeping of the Law, not the Law for the keeping of circumcision.
Therefore, if there happened to be found a Gentile who had never been circumcised (not out of conscience rejection of the rite but for some unwitting reason Paul leaves to the imagination) but he faithfully kept the Law of God, his keeping of the Law would be of more value in the sight of God than the Jew’s circumcision who ignored the Law or only kept it as outward show.
Perhaps Paul has in mind a situation much like Peter discovered in Cornelius.
“At Caesarea there was a man named Cornelius, a centurion of what was known as the Italian Cohort, a devout man who feared God with all his household, gave alms generously to the people, and prayed continually to God.” -Acts 10:1–2