Interpretation 1:
This refers to the circumcision of the heart (Romans 2:28). The Spirit of God circumcises
the hearts of people even if they are not heirs of the Jewish Scriptures. That is what the law is all about. Again, Paul concludes this passage by with God, who must be praised in all eternity. It is his judgment that matters (Romans 2:29). His wrath is real, first over the Jew and also over the Greek. All who do not deny him or distort his image, but who honour and thank him are entitled to his praise. Paul is an apostle for this obedience of faith
among the nations. The Spirit of Jesus Christ now causes this faithfulness to spread like blazing fire throughout the world. Paul is not comparing Gentile Christians with Jews. Instead, he compares Jews with non-Jews. His focus here is therefore not the extent of the people of God’s promises, but the need for Jew or Gentile to possess the inward circumcision of the heart.
Interpretation 2:
Cranfield1 believes that Romans 2:26–29 is actually about Gentile Christians. This immediately raises the question regarding whether Jews, who do not inwardly observe the law, fall outside the promise completely, in favour of a new Israel that consists of Christians (both Jews and Gentiles).
Interpretation 3:
In contrast to Cranfield, Schreiner2 is of opinion that Romans 2:14–16 identifies Gentiles who, despite their natural conscience and awareness of the law are nonetheless judged. However, like Cranfield also believes that Romans 2:26–29 does speak about Gentile Christians.
Interpretation 4:
Lyonnet3 interprets the inward aspect of being truly a Jew as referring to anonymous Christians, i.e. people who have touched by grace without consciously having become aware of it.4
26 So, if a man who is uncircumcised keeps the precepts of the law, will not his uncircumcision be regarded as circumcision?