What does circumcision of the heart mean in the Bible?

The Bible speaks of circumcision of the heart in passages like Romans 2:28-29, distinguishing it from physical circumcision. This spiritual circumcision denotes an inward change brought about by God's Spirit, enabling believers to genuinely worship Him. Rather than relying on outward rituals or the law, this transformation signifies a heart aligned with God's will, marked by true faith and spiritual obedience. It underscores the notion that acceptance before God is based on inner reality and divine action rather than mere external compliance.