And I will establish my covenant between me and thee and thy seed after thee in their generations for an everlasting covenant, to be a God unto thee, and to thy seed after thee. Genesis 17:7.FLB 77.1
As the Bible presents two laws, one changeless and eternal, the other provisional and temporary, so there are two covenants. The covenant of grace was first made with man in Eden, when after the Fall, there was given a divine promise that the seed of the woman should bruise the serpent’s head. To all men this covenant offered pardon, and the assisting grace of God for future obedience through faith in Christ. It also promised them eternal life on condition of fidelity to God’s law. Thus the patriarchs received the hope of salvation. FLB 77.2
This same covenant was renewed to Abraham in the promise, “In thy seed shall all the nations of the earth be blessed.” Genesis 22:18. This promise pointed to Christ. So Abraham understood it, and he trusted in Christ for the forgiveness of sins. It was this faith that was accounted unto him for righteousness. The covenant with Abraham also maintained the authority of God’s law. The Lord appeared unto Abraham, and said, “I am the Almighty God; walk before me, and be thou perfect.” The testimony of God concerning His faithful servant was, “Abraham obeyed my voice, and kept my charge, my commandments, my statutes, and my laws.” Genesis 17:1; 26:5.... FLB 77.3
The Abrahamic covenant was ratified by the blood of Christ, and it is called the “second,” or “new,” covenant, because the blood by which it was sealed was shed after the blood of the first covenant. FLB 77.4
The covenant of grace is not a new truth, for it existed in the mind of God from all eternity. This is why it is called the everlasting covenant. FLB 77.5
There is hope for us only as we come under the Abrahamic covenant, which is the covenant of grace by faith in Christ Jesus. The gospel preached to Abraham, through which he had hope, was the same gospel that is preached to us today....Abraham looked unto Jesus, who is also the author and the finisher of our faith. FLB 77.6
Cited from: The Faith I live by. Ellen G. White.