Part of the conditions of God’s covenant with Abraham required all males born to both him and his descendants to be circumcised on the eighth day. This was to serve as a constant reminder that they had been separated from other nations to be God’s special people.
“He then required of Abraham and his seed, circumcision, which was a circle cut in the flesh, as a token that God had cut them out and separated them from all nations as His peculiar treasure. By this sign they solemnly pledged themselves that they would not intermarry with other nations, for by so doing they would lose their reverence for God and His holy law, and would become like the idolatrous nations around them.” The Story of Redemption, 146, 147.
“By the act of circumcision they solemnly agreed to fulfill on their part the conditions of the covenant made with Abraham, to be separate from all nations and to be perfect. If the descendants of Abraham had kept separate from other nations, they would not have been seduced into idolatry. By keeping separate from other nations, a great temptation to engage in their sinful practices and rebel against God would be removed from them. They lost in a great measure their peculiar, holy character by mingling with the nations around them. To punish them, the Lord brought a famine upon their land, which compelled them to go down into Egypt to preserve their lives. But God did not forsake them while they were in Egypt, because of His covenant with Abraham. He suffered them to be oppressed by the Egyptians, that they might turn to Him in their distress, choose His righteous and merciful government, and obey His requirements.” Ibid.
Though God’s covenant with Abraham remains the same today and physical circumcision is no longer required as an act of separation for God’s people, the symbol represents a circumcision of the heart. Sin is to be cut away, eradicated from the life. When God circumcises our hearts, He gives to us a new heart (Ezekiel 36:26, 27). He puts His Holy Spirit within us so that we will walk in His ways and not in the ways of the world. With a new heart we are born again. We are His people, sojourners in this world, looking forward to the heavenly kingdom and the mansions that He has gone to prepare for us (John 14:2, 3).
Circumcision is an outward sign of an inward attitude and commitment. “Circumcise yourselves to the Lord, circumcise your hearts, you people of Judah and inhabitants of Jerusalem.” Jeremiah 4:4 NIV.