Romans 2:25-29b

Circumcision has value if you observe the law, but if you break the law, you have become as though you had not been circumcised. If those who are not circumcised keep the law's requirements, will they not be regarded as though they were circumcised? 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.

A man is not a Jew if he is only one outwardly, nor is circumcision merely outward and physical. No, a man is a Jew if he is one inwardly; and circumcision is circumcision of the heart, by the Spirit, not by the written code. Such a man's praise is not from men, but from God.

(v25-29, NIV)

Notice at the end how Paul notes that circumcision is circumcision of the heart by the Spirit. It is by the Spirit and not the written code. However, how does this work with what was mentioned earlier about uncircumcised becoming circumcised by keeping the requirements of the law? The thing is that the law isn't some terrible thing we should all run away from. However, if the law is without the Spirit, bad things happen. Paul is addressing in this chapter people who have the law but do not have the Spirit. We see that this produces external religion and ritual, but nothing internal. Since everything is external, they desire the praise of men, which is also external. This only leads to death because they were only relying on the law. However, if the law is met with the Spirit, this results in the internal circumcision of the heart. In our heart, our deepest desires become a growing passion for God's law. This is not merely external, but it is internal. Since it is internal, we find satisfaction in the praise of God and not the praise of men. In the end, this results in life; we have the Spirit. The Spirit is a necessary part of the equation. This is not merely external, but it is internal.