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.
After the Flood the people once more increased on the earth, and wickedness also increased.... The Lord finally left the hardened transgressors to follow their evil ways, while He chose Abraham, of the line of Shem, and made him the keeper of His law for future generations.16SDA Bible Commentary 1:1092.
This same covenant [the covenant of grace] 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 to 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” (Genesis 17:1). 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 26:5)....
Though this covenant was made with Adam and renewed to Abraham, it could not be ratified until the death of Christ. It had existed by the promise of God since the first intimation of redemption had been given; it had been accepted by faith; yet when ratified by Christ, it is called a new covenant. The law of God was the basis of this covenant, which was simply an arrangement for bringing men again into harmony with the divine will, placing them where they could obey God's law.17Patriarchs and Prophets, 370, 371.
If it were not possible for human beings under the Abrahamic covenant to keep the commandments of God, every soul of us is lost. The Abrahamic covenant is the covenant of grace. “By grace are ye saved” (Ephesians 2:8). Disobedient children? No, obedient to all His commandments.18SDA Bible Commentary 1:1092.
Abraham's unquestioning obedience was one of the most striking instances of faith and reliance upon God to be found in the Sacred Record.... Just such faith and confidence as Abraham had the messengers of God need today.19Testimonies for the Church 4:524.
From God's Amazing Grace - Page 133