25 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. – Romans 2:25-29
Circumcision was an act of cutting away the flesh from the most sensitive part of a male. It was an outward sign of cutting away the flesh from the heart (Deuteronomy 10:16). But the true act of circumcision as a spiritual act softening the heart of a person. The Holy Spirit is called sharper than a two edged sword:
For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and of spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart. – Hebrews 4:12
The process of the circumcision of the heart is an inward, spiritual process where God discerns the thoughts and the intents of the heart. He will reveal to us parts of our lives that he is dealing with and He will lead us to the cross where we can lay down our lives to take up His life. We are learning to bring every thought into captivity:
5 We destroy arguments and every lofty opinion raised against the knowledge of God, and take every thought captive to obey Christ,
6 being ready to punish every disobedience, when your obedience is complete. – 2 Corinthians 10:5-6
This idea was introduced in the Old Testament. When the law was given to Moses he reminded the people that God requires them to honour Him:
“And now, Israel, what does the LORD your God require of you, but to fear the LORD your God, to walk in all his ways, to love him, to serve the LORD your God with all your heart and with all your soul, – Deuteronomy 10:12
But he went on to say:
15 Yet the LORD set his heart in love on your fathers and chose their offspring after them, you above all peoples, as you are this day.
16 Circumcise therefore the foreskin of your heart, and be no longer stubborn. – Deuteronomy 10:15-16
We need to circumcise the foreskin of our hearts, not being hard hearted but soft hearted, sensitive to the leading of the Holy Spirit. Not stubborn and rebellious but willing and obedient to the leading of God but His Spirit.
As Paul says if we do not obey the word of God (the law) it is of no value to us. Having the word of God but not obeying it is hypocritical. But, those who obey the word of God and do not live by religious rituals will be revealed as righteous because they have put their faith in the Lord, and not in their own ability to perform. We do not look for the praise of men but to be approved of by God (John 12:43). There will be no better experience than to hear these words spoken to us by the Lord:
His master said to him, ‘Well done, good and faithful servant. You have been faithful over a little; I will set you over much. Enter into the joy of your master.’ – Matthew 25:23