Romans 2

"For he is not a Jew who is one outwardly ... but he is a Jew who is one inwardly; and circumcision is that which is of the heart, by the Spirit ..." (v28-29). What a radical idea! Though circumcision was originally intended to be a sign of God's covenant, it had become a moral requirement. Jews (and Gentiles) judged each other using cultural markers like circumcision, along with ancestry and wealth. But God sees our hearts and judges us there.

Faith in Jesus makes us holy in God's eyes. This "heart-circumcision" causes us to want to obey His commands.