Circumcision was a sign of the covenant of grace that God had made with Abraham (Genesis 17:6–14). Circumcision was no mere formality; to be circumcised meant to receive a sign of the deepest spiritual significance. Circumcision even pointed to the realities of regeneration and justification (Deuteronomy 10:16; Deuteronomy 30:6; Romans 4:11). It was a sign carved in flesh as a constant reminder of God’s promises to Abraham and his descendants. While this covenant sign did not guarantee that every recipient of it possessed the spiritual realities that it signified, it nevertheless functioned in every case as the official act of consecration, so that each recipient was made a member of the covenant community. Every male in Abraham’s household, whether sons or servants, as well as every male in the covenant community thereafter, was to receive this sign in his flesh if he was to be identified with God’s covenant people. Conversely, anyone who rejected the sign of the covenant was to be cut off from the covenant community (Genesis 17:14). To reject the sign of the covenant was to reject God’s promises in the covenant. Ultimately, it was to reject fellowship with the God who walked between the severed animal halves as a guarantee of his promises to Abraham (Genesis 15:1–21).1
2 At that time the LORD said to Joshua, “Make flint knives and circumcise the sons of Israel a second time.”