When Abram was ninety-nine years old the Lord appeared to Abram and said to him, “I am God Almighty; walk before me, and be blameless, 2 that I may make my covenant between me and you, and may multiply you greatly.” 3 Then Abram fell on his face. And God said to him, 4 “Behold, my covenant is with you, and you shall be the father of a multitude of nations. 5 No longer shall your name be called Abram, but your name shall be Abraham, for I have made you the father of a multitude of nations. 6 I will make you exceedingly fruitful, and I will make you into nations, and kings shall come from you. 7 And I will establish my covenant between me and you and your offspring after you throughout their generations for an everlasting covenant, to be God to you and to your offspring after you. 8 And I will give to you and to your offspring after you the land of your sojournings, all the land of Canaan, for an everlasting possession, and I will be their God.”
9 And God said to Abraham, “As for you, you shall keep my covenant, you and your offspring after you throughout their generations. 10 This is my covenant, which you shall keep, between me and you and your offspring after you: Every male among you shall be circumcised. 11 You shall be circumcised in the flesh of your foreskins, and it shall be a sign of the covenant between me and you. 12 He who is eight days old among you shall be circumcised. Every male throughout your generations, whether born in your house or bought with your money from any foreigner who is not of your offspring, 13 both he who is born in your house and he who is bought with your money, shall surely be circumcised. So shall my covenant be in your flesh an everlasting covenant. 14 Any uncircumcised male who is not circumcised in the flesh of his foreskin shall be cut off from his people; he has broken my covenant.” – Genesis 17:1-14
Circumcise yourselves to the Lord;
remove the foreskin of your hearts,
O men of Judah and inhabitants of Jerusalem; – Jeremiah 4:4
“You stiff-necked people, uncircumcised in heart and ears, you always resist the Holy Spirit. As your fathers did, so do you. – Acts 7:51
Then he who is physically uncircumcised but keeps the law will condemn you who have the written code and circumcision but break the law. 28 For no one is a Jew who is merely one outwardly, nor is circumcision outward and physical. 29 But a Jew is one inwardly, and circumcision is a matter of the heart, by the Spirit, not by the letter. His praise is not from man but from God. – Romans 2:27-29
How then was it (righteousness) counted to him (Abraham)? Was it before or after he had been circumcised? It was not after, but before he was circumcised. 11 He received the sign of circumcision as a seal of the righteousness that he had by faith while he was still uncircumcised. The purpose was to make him the father of all who believe without being circumcised, so that righteousness would be counted to them as well, 12 and to make him the father of the circumcised who are not merely circumcised but who also walk in the footsteps of the faith that our father Abraham had before he was circumcised. – Romans 4:10-12
…and you (Christians) have been filled in him (Christ), who is the head of all rule and authority. 11 In him also you were circumcised with a circumcision made without hands, by putting off the body of the flesh, by the circumcision of Christ, 12 having been buried with him in baptism, in which you were also raised with him through faith in the powerful working of God, who raised him from the dead. – Colossians 2:10-12
For neither circumcision counts for anything, nor uncircumcision, but a new creation. – Galatians 6:15
In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit, 14 who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory. And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption. – Ephesians 1:13; 4:30
The Abrahamic covenant was initiated by God with the promise to Abraham of descendants and a land in Genesis 12. It was confirmed as a matter of assurance to Abraham in a bloody covenant ceremony in Genesis 15. We humans, being what we are, need a reminder, one that we can’t easily ignore; especially if we are to remember something through the generations. So, in Genesis 17, God not only expands his promise, but also gives Abraham and his promised descendants, a sign and seal that cannot easily be ignored, the sign and seal of circumcision.
Circumcision is referred to as both a sign and a seal of the covenant. God is so emphatic about circumcision that he even says that it is the covenant. This is actually what is known as synecdoche, a figure of speech in which a part stands for the whole, such as the expression “a set of wheels” used to refer to a car, so “circumcision” can refer to the entirety of the Abrahamic covenant.
Everything of significance in the OT is really in reference to Christ (John 5:39, Luke 24:27). Circumcision, while very real and required, refers to something greater than the physical cutting off of the flesh. It is symbolic of the cutting off of our sinful hearts that are characterized by unbelief. The circumcision of the heart is a product of faith. God called Israel to circmcise their hearts to avoid judgement (Jeremiah 4:4). We understand that circumcision was always about more than just cutting off a little piece of flesh.
In my opinion, the significance of circumcision wasn’t really understood until the New Covenant when we find that Christ is our circumcision, it is he who cuts away our stony hearts and gives us hearts of flesh by the work of the Holy Spirit. This is the essence of the New Covenant, that we are made new and eventually he will make all things new. Christ lived a perfect life of obedience on our behalf so his righteousness could be credited to us. That perfect obedience included his personal circumcision at eight days. He was circumcised on our behalf so he could be our circumcision.
The New Testament analogue to circumcision is baptism. Just as the physical act of circumcision under the Old Covenant did not put away sins, but in fact pointed to the promise in the Abrahamic covenant that does put away sins, so baptism itself does nothing to cleanse our sins but points to the act that does, the death and resurrection of Christ, the fulfillment of the Abrahamic covenant promises.
The seal indicates ownership. Christians are sealed with the Holy Spirit of promise, the promise that goes all the way back to Abraham and is completed in Christ.
So, the sign of circumcision pointed to Christ, THE seed of Abraham, who is our circumcision and the seal of circumcision was fulfilled in the seal of the indwelling Holy Spirit given to all believers in Christ.
If you would like to do more indepth reading on the concept of covenant in Scripture, I recommend this book, Sacred Bond. Click on the book and you will be taken to Amazon where you can purchase a copy.