When the nation of Israel was in covenant relationship with God circumcision was a requirement for the sons of Israel and any uncirumcised male was cut off from that nation:
"This is my covenant, which ye shall keep, between me and you and thy seed after thee; Every man child among you shall be circumcised. And ye shall circumcise the flesh of your foreskin; and it shall be a token of the covenant betwixt me and you...And the uncircumcised man child whose flesh of his foreskin is not circumcised, that soul shall be cut off from his people; he hath broken my covenant" (Gen.17:10-11,14).
On the other hand, circumcision profits no one during the Church age, as witnessed by Paul's words here:
"For in Jesus Christ neither circumcision availeth any thing, nor uncircumcision; but faith which worketh by love" (Gal.5:6).
The Scriptures reveal that when the nation of Israel was in a covenant relationship with the LORD the children of Israel were a special people unto Himself:
"For thou art an holy people unto the LORD thy God: the LORD thy God hath chosen thee to be a special people unto himself, above all people that are upon the face of the earth" (Deut.7:6).
On the other hand, during the Church age there are no special people unto the LORD except for believers and in the Body of Christ there is no distinction between the Jews and those of other nationalities:
"And have put on the new man, which is renewed in knowledge after the image of him that created him: Where there is neither Greek nor Jew, circumcision nor uncircumcision, Barbarian, Scythian, bond nor free: but Christ is all, and in all" (Col.3:10-11).
These facts serve to prove that when the LORD's program for Israel is in view then that program cannot be about the Body of Christ because His two different programs are mutually exclusive. In other words, when the Divine plan toward Israel is in effect then the children of Israel are above all people on the face of the earth so therefore it is impossible that at the same time the Divine plan is also toward the Body of Christ where there is no difference between the two.
So the New Covenant which was promised to the house of Jacob and the house of Israel is exclusively in regard to God's program for Israel and has nothing to do with the Body of Christ.