What does the Bible say about circumcision of the heart?

Circumcision of the heart is a biblical concept that refers to the spiritual transformation that occurs when one is regenerated by the Holy Spirit. In Philippians 3:3, Paul emphasizes that true circumcision is not merely a physical act linked to the Jewish covenant but a deep, inward reality that God performs. This spiritual circumcision is characterized by worshiping God in Spirit and truth, as well as rejoicing in Christ Jesus, delineating the true people of God from those who trust in mere external rites.

Furthermore, this transformation results in a new nature that prioritizes faith in Christ over confidence in the flesh. The flesh, as described in Jeremiah 17:9, is deceitful and wretched, thus the true child of God recognizes their inability to achieve righteousness apart from Christ. Ultimately, the heart must be changed to see Christ as the sole source of salvation, marking a critical aspect of one's faith journey as a believer.