Romans 2:27

The one who is not circumcised physically and yet obeys the law will condemn you who, even though you have the written code and circumcision, are a lawbreaker.

(v27, NIV)

The last two verses were about this reversal that takes place. People who are circumcised can undo their circumcision by breaking the law. However, uncircumcised people can become as if they are circumcised by keeping the requirements of the law. These circumcised Jews boasted in the law and their circumcision, but these uncircumcised Gentiles are becoming as if they are circumcised. This is quite shameful because they are somehow "getting it" without having the law. As it says here in verse 27, they condemn you. "You" is referring to those who are circumcised, the Jews who have the law and circumcise themselves. It's like some big muscular guy who worked out every day and boasted in his strength. However, one day he is somehow beaten in an arm wrestle against some tiny scrawny kid who doesn't even know what "working out" is. That really is quite mind-boggling as to how that could happen and it would certainly confuse this big muscular guy who just lost. Clearly, there is something that the big muscular guy didn't quite understand or get because he worked hard and was confident in his muscles but was defeated by someone who he would've bet $1000000 would never have a chance of winning in an arm wrestle. Yet, the Jews stand dumbfounded or in disbelief as Paul tells them that their circumcision is undone and the Gentiles are becoming as if they are circumcised. The Jews had the law and they had the advantage. However, those without the law are somehow getting "it". The Jews should be getting "it", having all the advantages of being God's chosen people and being given the law. However, the uncircumcised obey the law and condemn the Jews. This is quite sad.

The Jews become works and rules based. They tried to earn their way to heaven. As Paul mentions earlier, the Jews were hypocrites and unrepentant. When we are saved by the saving work of Jesus Christ, we do not continue in sin. Instead, there is a transformation process and we grow in righteousness. This doesn't mean we're perfect, but we grow deeper and deeper entangled in sin. Do not become like the hypocritical Jews who boasted in the law and in the flesh. Instead, hear, repent and receive what he freely gives; not by your own efforts by his alone.