Question: “Why does God institute circumcision in Genesis, what’s that got to do with anything?”
Answer: Circumcision raises a number of issues, here’s three of them:
Firstly, it seals the contract:
“As for me, this is my covenant with you: You will be the father of many nations. No longer will you be called Abram; your name will be Abraham” (Gen 17:4-5).
So that was God’s part of the contract, then the Lord said, “As for you... You are to undergo circumcision, and it will be the sign of the covenant between me and you. For the generations to come every male among you who is eight days old must be circumcised” (Gen 17:9-10), which was Abraham’s part of the contract. Abraham stood up and acknowledged his part of the agreement.
“On that very day Abraham took his son Ishmael and all those born in his household or bought with his money, every male in his household, and circumcised them, as God told him” (Gen 17:23).
Secondly, circumcision informs us about our fallen state and the nature of original sin.
- "I, the Lord your God, am a jealous God, visiting the iniquity of the fathers on the children" (Exod 20:5).
- We can easily miss the importance of the phrase "iniquity of the fathers" or “sins of the fathers” thinking that a deed a father has committed affects his posterity in a circumstantial way. For instance, if a man decides to steal something and gets caught, his family will have to fend for themselves while the man of the house is paying his debt to society in prison. So, in that way the sin of the father (theft) directly affects his children who now have no father figure in their life. But the phrase "sins of the fathers" carries more weight than that.
- A woman inherits the sinful nature from her father and she herself will sin, and we may read of a "sin of a mother" but not "sins of the mothers being visited upon the children." The phrase “sins of the fathers” highlights our fallen nature being passed from one generation to the next through the fathers but not the mothers. Let us remember that it was the men who needed to be circumcised, no such ruling existed for women.
- The act of circumcision directly affects the organ of the physical body used for procreation. God uses many ways of speaking to us and drama, parallels, shadows, poems, types, the natural world, and physical alterations of the human body all count towards the big picture that God is painting.
- Faith in Christ saves us from the law of sin and death, and the “futile way of life inherited from your forefathers” (1 Pet 1:18). Jesus had a human mother but not a human father, so he shared in our humanity, but he did not inherit the flaw or blemish the rest of humanity has. The human “heart is deceitful above all things and beyond cure” (Jer 17:9). Jesus did not have that deceitful heart, but he did have the human frame that we all share.
Thirdly, circumcision is a reminder that we all ought to let the beauty of Jesus be seen in us.
“A person is not a Jew who is one only outwardly, nor is circumcision merely outward and physical. No, a person is a Jew who is one inwardly; and circumcision is circumcision of the heart, by the Spirit” (Rom 2:28-29).
Moses understood this and said, “Therefore circumcise the foreskin of your heart, and be stiff-necked no longer” (Deut 10:16).
Our hearts can get calloused, hardened and rough - Jesus said, "Learn from me, for I am gentle and humble in heart" (Matt 11:29). And the apostle Paul said, “Let your gentleness be evident to all” (Eph 4:5), and, "I want to know Christ ... becoming like him" (Phil 3:10 NIV).