The rite of circumcision predates the giving of the Torah to Moses at Sinai, of course, and was given to Abraham as a sign of separation from his pagan past (Gen. 17:10-14). As a literal cut into the reproductive organ of flesh, it was meant to (intimately) put the mark of the LORD at the point of contact with the lower "reproductive" nature. As such, it was inherently symbolic, since no fleshly operation could sever the connection of the yetser hara from the loins of man (Gal. 6:8).
The Torah and Prophets confirm this understanding that the physical rite itself was intended to signify a spiritual change within a person. For example, "Circumcise, therefore, the foreskin of your heart, and be no more stiff-necked'" (Deut. 10:16). And again, "Circumcise yourselves to the Lord, and take away the foreskins of your heart, you men of Judah and inhabitants of Jerusalem, lest My fury come forth like fire and burn that none can quench it, because of the evil of your doings'" (Jer. 4:4). Thus it is clear from the Tanakh that "circumcision" was always intended to be sign of inward transformation rather than an external ritual.
Moses and the death of self
Moses himself provides an interesting case study. In Exodus 4:24-26 we read that the LORD sought to "kill" Moses since he failed to circumcise his family. What does this mean? It is evident that no man can see God and live (Exodus 33:20; Deut. 34:10), yet Moses is said to have been able to speak with God panim el-panim - "face to face." In other words, Moses had to die in order to commune with the LORD. His flesh had to be "rolled away" so that he could experience the Presence of the LORD. To seek God's face is the death sentence of our basar - our "flesh" and its ties to the carnal connections with the world.
The Second Circumcision Foretold
Moses was unable to lead the children of Israel into the land of promise. Rather it was Joshua the son of Nun - a type of Mashiach - who went over the Jordan. However, before Israel could enter the land of promise, they had to be circumcised again at Gilgal, the entrance to Canaan (Josh. 5:2-9). In Hebrew, "Gilgal" means "to roll," as in rolling off from us "the flesh" or the principle of lust that governs the lower nature. This second circumcision is prophetic of the work of the Mashiach Yeshua done on our behalf.
The Brit Chadashah reaffirms that true circumcision is a matter of inward transformation rather than mere external ritual:
For no one is a Jew who is merely one outwardly, nor is circumcision outward and physical. 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 2:28-29.
The Circumcision of the Mashiach
Indeed, true inward circumcision is a matter of a heart transformed by the grace of God given through the love of the Mashiach Yeshua:
Therefore remember that at one time you were Goyim in the flesh, called "the uncircumcision" by what is called the circumcision, which is made in the flesh by hands (Eph. 2:11); [but] in Him also you were circumcised with a circumcision made without hands, by putting off the body of the flesh, by the circumcision of the Mashiach, having been buried with Him in baptism, in which you were also raised with Him through faith by the powerful working of God, who raised the Mashiach from the dead. And you, who were dead in your trespasses and the uncircumcision of your flesh, God made alive together with Him... (Col 2:11-3).
Flesh and blood cannot inherit the kingdom of God (1 Cor. 15:50), and those controlled by the sinful nature (yetzer hara) cannot please God (Rom. 8:8). Before coming before the LORD in the Mishkan (tabernacle), the worshipper had to face the brazen altar where the smoke of flesh ascended up in sacrifice. No one could approach the LORD apart from the shedding of blood and the offering up of the flesh.
Yeshua the Mashiach offered His flesh and blood upon the cross as the Sacrifice for the life of mankind (John 6:51) We cannot approach the LORD apart from His sacrifice on our behalf. And yet we are identified with His sacrifice - we are to follow Him and count ourselves crucified with Him (Rom. 6:6). This requires an act of faith that effects an inward heart change. We "reckon ourselves" dead indeed to the flesh (Romans 6:11) and thereby put away the deeds of the flesh (Col. 3:5). We die in order to live. Through teshuvah (repentance) we turn our back forever on the flesh, take up our cross daily, and follow the Master (Luke 9:23).
Rebirth and the Second Circumcision
Nicodemus was "the teacher of Israel" who came to Yeshua by night to ask about salvation (John 3:1-21). His understanding appears to have been entirely rabbinical, thinking that Yeshua's concept of salvation had to do with physical birth and ritual circumcision. Yeshua corrected his faulty thinking by pointing to spiritual birth with inward circumcision as the way to the Father. The new birth Yeshua spoke of is a birth of "water and of the Spirit." It is an opening up and coming alive in the realm of the Spirit.
It takes more than flesh to make one a Jew who stands approved in God's sight. What more does it require? It takes walking "in the footsteps of the faith that our father Abraham had before he was circumcised" (Rom. 4:12b). Just as God chose Abraham before he was circumcised, so Gentiles who trust as did Abraham "are the real circumcision, who worship by the Spirit of God and glory in Christ Jesus and put no confidence in the flesh" (Phil. 3:3). And you are a child of Abraham, if you are trusting in Yeshua as your Savior (Gal. 3:7).
The Necessity of Circumcision
Should a Christian be circumcised, then? Absolutely - and in fact, if you are uncircumcised you are lost and will suffer eternally. But this circumcision is a spiritual act, performed by the "hands of the Messiah" and received through an act of faith in His love. Indeed, in the coming Messianic kingdom, Isaiah foretold the time when only circumcised people would be allowed to enter the new city of Zion (Isa. 52:1-2). This is a picture of our future estate with Yeshua as Mashiach ben David.
But if the question is whether a Christian should be circumcised in the physical sense, as a Rabbinical rite that is intended to symbolize inclusion into Israel (i.e., "conversion" to Judaism), the answer is a resounding "No!" If you have trusted in Yeshua as your Savior you have no need for any further conversion. You are already "grafted in" to the Olive Tree of Israel (Rom. 11:17). Circumcision was not required of the first converts to the way of Yeshua (cf. Acts 15:1-21; Gal 5:2-4). For Jewish believers in the Mashiach who have already been circumcised, there is no need to become "uncircumcised," but the Brit Chadashah is emphatic that circumcision as a Rabbinical ritual to effect inclusion into Israel is worthless.
In fact, depending on your motivation, the desire to be circumcised can be spiritually damning:
Look: I, Paul, say to you that if you accept circumcision, the Messiah will be of no advantage to you. I testify again to every man who accepts circumcision that he is obligated to keep the whole Torah. You are severed from Messiah, you who would be justified by the Torah; you have fallen away from grace. (Gal. 5:2-4)
How so? Did not the LORD institute circumcision as an "everlasting covenant" (Gen. 17:3)? Indeed He did, but if someone who is uncircumcised seeks to be "justified" by means of the commandment in the Torah (i.e., ritual acts or works), he is thereby obligated to keep the whole Torah, and the provision for sacrifice through the Mashiach under the terms of the Brit Chadashah will no longer be in effect (Gal. 3:10). We are justified by trusting in the LORD, and not by the deeds of the Torah (Rom. 3:20).
The circumcision made "without hands" is an operation of the Holy Spirit Who writes the inner meaning and truth of the Torah upon our hearts. True circumcision represents the death of the selfish impulse within our hearts (a miracle if ever there was one!) and is merely prefigured by the physical ritual as practiced by Rabbinical Judaism. Even Moses foresaw that day when the outer would become inner, as he wrote:
"The LORD your God will circumcise your hearts and the hearts of your descendants, so that you may love him with all your heart and with all your soul, and live" (Deut. 30:6).
A New Principle of Generation
God wants us to stop "reproducing in the flesh" and begin to reproduce in the Spirit. Circumcision, then, is a symbol of such inner transformation, a picture of an inner fruitfulness that only the Holy Spirit can work within us. It is a picture of grace, a seal of the Spirit, an identification with the way of the LORD Yeshua, who took up His cross and poured out His heart for us in sacrificial love. Such true circumcision is the end of all confidence "in the flesh" (Phil. 3:3).