Circumcision is supposed to be a sign of God’s covenant with the people of Israel, but it has become a mark on the body that has little to no effect on how God’s people live. Now God speaks a rather shocking message. Judgment is coming on all nations—those inside and those outside the covenant—whose people are not distinguished by a mark that truly matters. God calls this judgment the circumcision of the heart—a strange phrase indeed. The difference is between the inside and the outside, the superficial and the real. God has had enough, the prophet says, of those who go through the motions, confident in their wisdom, strength, and wealth. God wants a people who are truly devoted to knowing and honoring Him.