The covenant of grace is the one eternal covenant and there is no other, which is the covenant that created Israel in the beginning and creates Israel now. When G-d promised blessing to and through Abraham no previous promise of grace and blessing had been given to anyone in the world, not even to Noah. Only mitigated judgment had been promised to Noah, and to sinful Adam nothing had been promised but a curse. Noah was only promised that the world would not be destroyed by water. He was not promised that it would be blessed and not forever destroyed. Only Abraham was promised this.
It is true that a promise of the seed of the woman had been made, but this promise was made to the serpent as a threat, a certainty of judgment. It was necessary to interpret it, to read into it, to hear hope in it for Adam-kind. G-d arranged for the man and the woman to overhear the promise he made against the serpent and the seed of the serpent, but He did not directly address either of them in doing so. Only with Abraham and his seed, and to Abraham and his seed, was a promise given that the curse would be turned into a blessing. This covenant of grace and blessing was then made to be the covenant of circumcision.
When by the prophet Jeremiah G-d stated that Israel had broken His covenant, He also promised that He would make His covenant anew with Israel. This is the only translation in English that accurately reflects the Biblical revelation of he covenant of G-d. It is the one eternal covenant made anew.
If it is eternal, why does it need to be made anew? Although G-d speaks of His covenant with Israel as being eternal, He also speaks of it as being broken. How are we to understand this? We must begin by stating clearly that G-d announced His covenant with Abraham unilaterally, and made it unilaterally and unconditionally. Abraham was only required to be Abraham. His seed was only required to be his seed. Israel was only required to believe G-d and accept His covenant. It is here where G-d found the problem which He called the breaking of His covenant. Israel did not believe in Him to obey Him as children. Instead they turned to worshipping idols. Only a portion of Israel adhered to Him. When it came about that they did obey Him, but without faith, as slave servants, this He called breaking His covenant.
Then He said to them, You have broken my covenant by not adhering to it from the heart. Nevertheless, I will make my covenant with you anew. I will circumcise your heart. Although G-d alone guaranteed the covenant of grace and blessing which He made with Abraham and his seed, He treated the seed of Abraham as though everything depended upon Israel. When Israel's heart failed and turned away from Him, He then began to win her heart back and put a new spirit within her. By treating Israel as having the power to break the covenant that could not be broken, G-d actually gave her this power, but He did so only in His Messiah.
For in His Messiah, G-d was able to be, as it were, broken Himself, to have Israel break His covenant and His heart, but without ever breaking her heart, or His covenant with her. He did this simply by saying, Though you have broken my covenant, I am simply going to repeat my covenant with you. I am going to make my covenant anew with you, just as I made it with Abraham, Isaac and Jacob and all Israel at Mount Sinai. For from the beginning it has been my covenant of grace and forgiveness, and the covenant of the blessing of my Instruction. Through it you will again become one whole Adam. For I am the G-d who heals you.
