It was God that laid the theological foundation when He commanded Abraham to circumcize all the male infants born to the chosen people.
Circumcision was a sign given first to Abraham and his household and later, to the Old Covenant nation of Israel. One purpose of circumcision was identification. Initially, circumcision identified those who belonged to Abraham’s household. Under the Old Covenant, that period of time from Exodus 19 to Acts chapter 2, circumcision identified ancient Israel as the physical people of God. In both instances, circumcision was a physical sign showing one’s physical identification.
The greater purpose of circumcision was to point to the coming age of the Spirit in the New Covenant in which the church, Abraham’s true spiritual descendants (Gal. 3:16, 29), receive true circumcision of the heart (the forgiveness of sin and everything that accompanies salvation) and are placed within the family of God. In the NC, physical circumcision gives way to baptism as the outward identification that one has become a part of the people of God, a spiritual descendant of Abraham and a part of the true people of God, the church (Col. 2:9-12).
In Abraham’s case, circumcision was an outward sign that he truly believed. Abraham had been given the gift of faith, experienced the forgiveness of sin, and is an OT example of imputation. Abraham believed God and his belief was credited to him as righteousness, acceptance with God (Rom. 4:7-25).
Second, Abraham was justified and had his sins forgiven before he was given the sign of circumcision, indicating that he was justified by faith. The outward physical sign of circumcision did not contribute to his salvation in any way.
Circumcision was the sign of the covenant God made with Abraham. The Abrahamic Covenant was God’s promise to Abraham that he would create a people, rescue them from slavery, and bring them into a land, Canaan (Gen. 17:1-14).
Every male child born in Abraham’s household was to be circumcised when he was eight days old (Gen. 17:12).
Both the OC and the NC are contained within the Abrahamic Covenant. The promise made to Abraham to create a people and bring them into a land is first illustrated under the OC in the nation of Israel, and then fully accomplished in the NC by the death of Christ (Heb. 3:7-4:11).
The Abrahamic Covenant is also called the Covenant of Circumcision (Acts 7:8).
Although Abraham believed, belief was not a requirement for circumcision and inclusion in Abraham’s household.
The era of the OC can be defined as the period of time from the giving of the Mosaic Law on Mt. Sinai (Ex. 19) to the pouring out of the Spirit and the beginning of the church in Acts 2.
Circumcision continued under the OC as an ongoing obligation to the Abrahamic Covenant and as a restated requirement of the Old Covenant (Lev. 12:1-3, John7:21-22).
Circumcision for the nation of Israel was a physical sign that they were the people of God under the OC (Phil. 3:5-7).
Any slave or foreigner living in Israel had to be circumcised before they could eat the Passover (Ex. 12:43-48).
When Scripture evaluates the spiritual condition of the OC nation of Israel, the verdict is always an indictment of unfaithfulness and unbelief. While there was always a believing remnant, as a whole, Israel was unbelieving (Jer. 9:25-26, Mal. 3:6-9, Rom. 11:4, Heb. 8:7-13).
Israel was repeatedly called to repent. The language of repentance was a call for circumcision of the heart (Deut. 10:14-15, 30:6, Jer. 4:4, 9:25-26).
The sign of circumcision was an outward physical indication that one was either a physical descendant of Abraham, a physical part of the OC community of ancient Israel, or both. But the outward sign of physical circumcision was not an end in itself. It was a gospel picture of the need for circumcision of the heart, the true forgiveness of sin, and inclusion in the true people of God. God’s indictment against all of those who were circumcised, including Israel, is an indictment of unbelief because they were satisfied with mere physical circumcision instead of true spiritual circumcision – circumcision of the heart (Acts 7:51-54).
Under the NC, physical circumcision means nothing. What circumcision once pictured and anticipated has been fulfilled and realized by the death of Christ. The forgiveness of sin is called circumcision of the heart (Rom. 2:28-29).
Every believer experiences circumcision of the heart (Col. 2:9-12).
Circumcision for the sake of pleasing God is viewed negatively and is divisive in the church, the true people of God (Gal. 2:12-13, Titus 1:10-11).
No one can gain acceptance with God by good works. What counts is genuine faith evidenced in the new heart and the changed life (Gal. 5:1-6, 6:15).
God accepts us when he circumcises our hearts, which results in the forgiveness of sin and unconditional acceptance (Acts 20:21, Phil. 3:2-3).
The primary purpose of baptism is to acknowledge or testify to God that we are his. Baptism is the believer’s formal profession of faith and pledge of a good conscience that is the result of having received the forgiveness of sin (1 Pet. 3:21).
Examples of baptism in the NT immediately follow conversion (Acts 8:34-38, Acts 16:33).
Baptism is identification with Jesus in his death and resurrection. It has no direct connection to OT circumcision but it correlates to circumcision of the heart, meaning that baptism is not intended for infants who cannot profess the gospel, but it is intended for those who repent and believe the gospel and have experienced spiritual circumcision of the heart, the forgiveness of sins (Colossians 2:9-12).
Just as circumcision once identified the physical descendants of Abraham and OC Israel, water baptism is our identification with God in Christ, indicating that our sins have been forgiven and we have received circumcision of the heart, the forgiveness of sins (Col. 2:9-12).