Hi!
Jus' my two cents towards the discussion ... well, perhaps better said to be 5 cents because of it's length.
Circumcision was the sign of the Old Covenant which God established with Abraham and his natural descendants, (Gen 17:10-11). Abraham was already a believer before he was circumcised. On the grounds of that faith he had also received the gift of righteousness. Even though he entered it as a stranger, Abraham had entered the promised land because of his faith in God, .
When Abraham left Ur of the Chaldees behind, he had already received the promise that in him all the generations of the earth would be blessed, (Gen 12:3). He had received the promise that he would be an heir of the world, (Rom 4:13). The greatest which the world had to give would spring from him, namely Christ and those who are in Christ.
Abraham had himself circumcised with his son Ishmael and more than three hundred members of his household. But the son of the promise had not yet arrived. The slaves, and those who were born in the house of their master, would later wear the sign of circumcision as the people of Israel. It was not in itself a sign of belief but an indication that a man belonged to the natural offspring of Abraham. For Abraham himself, however, it was a sign of the righteousness of faith, (Rom 4:11). [This explains why a circumcised people did not enter into the promised land because of unbelief; instead, an uncircumcised people under Joshua did enter in]. A circumcised nation perished in the wilderness because they did not believe God or put their trust in Him (Heb 3:19). Circumcision was an external, hidden sign. It was not possible to tell from a man's face whether he belonged to the people of God. This hidden sign was associated with the procreation of natural life.
The Old Covenant had a sign in the flesh and it was a Covenant for the natural descendants. In the New Covenant there is a sign in the heart and a Covenant in the spirit; that is: in the invisible world. The New Covenant is concerned with the inner man; with his understanding and with his heart.
"This is the Covenant that I will make with the (spiritual) house of Israel after those days, says the Lord, I will put my laws into their minds and write them on their hearts, and I will be their God, and they shall be my people", (Heb 8:10). The New Covenant is not in any manner a continuation of the Old Covenant. While it runs parallel, it nevertheless belongs to a higher reality. The two Covenants are like two roads; one which goes over the earth and the other through the heavens. In the Old Covenant, everything was focused to the earth and the world of the physical senses. In the New Covenant, which rests on better promises, everything is focused on "things above"; in the the "heavenly places".
There was an earthly tabernacle in the Old Covenant, and there is a heavenly, true tabernacle in the New Covenant (Heb 8:2). Then there were earthly priests, now there is a heavenly priesthood (1Peter 2:9). There was an earthly high priest, now there is a heavenly High Priest (Heb 8:1). There was a shadowy law of Sinai, now there is a law of the Spirit, 'for when there is a change in the priesthood there is necessarily a change in the law as well' (Rom 8:2; Heb 7:12). The Old Covenant was made with the natural people of Israel, and the New Covenant with the spiritual Israel of God.
The Old Covenant had a circumcision made by hands, which left an outward mark on the body. The New Covenant has a circumcision which is not made with hands. 'In him also you were circumcised with a circumcision made without hands by putting off the body of flesh in the circumcision of Christ; and you were buried with him in baptism' (Col. 2.11-12). The circumcision of Christ, in contrast to that of Moses, (John 7:22), is the manner in which the Christian is circumcised by the Holy Spirit. The circumcision of the heart therefore is what has taken the place of the Old Covenant circumcision;
Circumcision in the Old Covenant was only for male descendants, for 'by the will of man' children were conceived, (Gen 17:10 & John 1.13). The Old Covenant applied only to the natural offspring. The New Covenant counts only with the spiritual man and knows no distinction between man and woman, (Gal 3:28). The circumcision of the heart and the testimony to this in baptism, is for all children of God without distinction of sex. "They were baptized, both men and women", (Acts 8:12). When Paul boasted about this, it was not in the mark which he had on his physical body as a natural son of Abraham, but upon the mark of Jesus which had come about by the circumcision of the heart, (Gal 6:15-17).
What is the parallel between the circumcision of the Old Covenant and the circumcision of the heart in the new? Faith on Abraham's part preceded circumcision. The first thing a person must do to be included in the New Covenant is to repent and put his faith in the promises of God. What do these promises say? The answer is: "But to all who received him, who believed on his name, he gave power to become the children of God", (John 1:12).
Through the power of the life-giving Spirit, a new creation is born out of the old dead man. The completely new life frees itself from the old. The new man has been born and he must be made free from the old life. The new man is now separated from the old. This is a clear sign in the spiritual world that a man has become a child of God. He wears the mark: "Let everyone who names the name of the Lord depart from iniquity", (2Tim 2:19).
In the same way that the umbilical cord, joining together mother and child, has to be severed after a natural birth, the old man is severed from the new by a circumcision which takes place without hands. By virtue of the circumcision of the heart, the reborn man is freed from his old life and receives the power to live in newness of life. This is the circumcision of Christ, for "if the Son makes you free you will be free indeed", (John 8:36). Although this forms a first beginning, the new man has become a citizen of the Kingdom of God and his name is recorded there.
Baptism symbolizes the fact that this circumcision has taken place. The old life has been left behind in the water, buried as an after-birth. The new man emerges as a child of God, and in his heart he wears the 'hidden' sign of the Covenant: circumcision. His new heart is an indication that Jesus has given him eternal life. "Real circumcision is a matter of the heart, spiritual and not literal", (Rom 2:29). It is a circumcision after the law of the Spirit and not after the law of Sinai. "For we are the true circumcision, who worship God in Spirit and glory in Christ Jesus and put no confidence in the flesh", (Phil 3:3).
The circumcision of the heart belongs to the process of spiritual birth. The prophet said to those who were born under the Old Covenant, "And as for your birth, on the day you were born your umbilical cord was not cut", (Ez 16:4). They were not separated from the old man.
After the circumcision and resurrection to new life, a person has not simply become a child of God but he is also included in the body of Christ, that is the faithful church. "For by one Spirit are we all baptized into one body", (1Cor 12:13). For this reason also testify about "the circumcision of Christ". The result of this circumcision is that the new man, like a living cell, takes up his place in the mystic body of Christ. Also, in the New Covenant the seed of Abraham is circumcised. This seed is Christ, and all those who are in Christ, (Gal 3:16-29).
Through this circumcision of the heart a separation takes place between the old and the new man. The old man had contact with the powers of darkness, which were at work in him, (Eph 2:2). The new man is born as a result of the contact between the powers of the Spirit of God and the spirit of man. Now we can say: "Abba, Father". The eternal judgment, the absolute separation between good and evil, begins to take place here in a human life. Abraham believed that he would be the heir of the world, (Rom 4:13). The spiritual circumcision is the sign of the promise of being a child of God. We are heirs in the spiritual world, heirs of God and fellow heirs with Christ, (Rom 8:17). This is a matter of faith, even though we only see the early beginnings.
The circumcision of the heart is the spiritual reality which was foreshadowed by the circumcision of the Old Covenant. It 'brands' a person as a child of God.
---
Those denominations which substitute infant baptism for circumcision accept again the natural line of the generations. Faith cannot be required or expected from an infant who is to be baptized. The words of the apostle about circumcision apply equally well to the sprinkled infant, "If you receive circumcision Christ will be of no advantage to you", (Gal 5:2). For this reason many of the traditional denominational doctrines never exceed the spiritual standards of ancient Israel. Instead, by their insisting to permit infant baptism testifies that they remain on the same level as the Old Testament and lack opportunity to develop as spiritual people. Only those who have a genuine share in the New Covenant are called 'the seed of Abraham', (Heb 6:8).
---
