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. (Romans 2:29)
The Jewish people and the new Jewish converts to Christianity of his day insisted that God was interested in rule keeping. In essence, they thought that laws could save. That is why they emphasized the importance of circumcision, both for the Jew as well as for the Gentile believer. And because they lived this religious life, they felt qualified to teach others. People are easily impressed by such people.
How many Christians live this way today? I am a good Christian because I tithe and give generously. I am a good Christian because I attend prayer meetings and Bible studies. I am a good Christian because I never steal and I am kind to others. They are saying that it is my religious life that saves.
God reminds us that it is the “circumcision” of the heart that matters. In other words, God does not look at external appearances and law keeping. He is interested in our hearts.
Does that mean if our hearts at pure, it doesn’t matter how we live? No. Out of a pure heart, right actions will follow, but right actions alone without checking our hearts is a dangerous place to be. When the Spirit moves our hearts and our highest goal is to please God, then a life of morality and integrity and wholeness will follow.