Who is part of the nation of Israel?  Who are God’s chosen people?  Paul explains:

Romans 2:25-29 For circumcision indeed is of value if you obey the law, but if you break the law, your circumcision becomes uncircumcision. 26 So, if a man who is uncircumcised keeps the precepts of the law, will not his uncircumcision be regarded as circumcision? 27 Then he who is physically uncircumcised but keeps the law will condemn you who have the written code and circumcision but break the law. 28 For no one is a Jew who is merely one outwardly, nor is circumcision outward and physical. 29 But a Jew is one inwardly, and circumcision is a matter of the heart, by the Spirit, not by the letter. His praise is not from man but from God.

The first observation I see here is that a transgression of the law in one place is a transgression of the whole law.  This is an indictment of Jews, but it is something more than that, it is an indictment of everyone who is unable to keep the entire law.  Thus, in reality, everyone has uncircumcised hearts and is completely dependent upon the mercy of God.  Paul even includes a jab to the descendants of Abraham implying that there are physically uncircumcised Gentiles who understand the meaning of circumcision better than those who are physically circumcised.  Some Jews simply missed the point that circumcision is the outward sign of a covenant which should have motivated the bearer of the sign to obey God with all of his heart, mind, soul, and strength.

Moving beyond this indictment of their impartial understanding of circumcision, Paul does not stop, but he goes to the extreme of warning them that they might not really be Jews.  Paul is not being hyperbolic, rather, he is stating clearly that it is possible to appear to be a Jew, but to be a Gentile inwardly.  This is certainly controversial territory for Paul to be crossing, but who better to do it than one who once trusted in all of the outward regalia but then came to see it as refuse (skubala)?  Paul is not here telling them not to be circumcised, but he is telling them that an outward circumcision is meaningless without the circumcision of the heart.

Let’s take this indictment of the Jews and apply it today to our own hubris.  Whatever church attendance record we might hold, whatever amount of money we have tithed, whatever the classy state of our Sunday attire, we must cling with our heart, mind, soul, and strength to the Father through the Lord Jesus Christ by the power of the Spirit.  If we fail at this central pillar of Christianity, a humble love for God, then all else we would do is folly.  Let us humble ourselves and be the truly repentant Israel whom God is calling to Himself.