What does the Abrahamic covenant serve as the foundation for?

Les explains that the Abrahamic covenant becomes the very foundation of everything as the narrative moves into the New Testament, the appearance of Christ, His earthly ministry, His rejection by Israel, and then the Church Age after the conversion of Saul of Tarsus. He ties this to Genesis, where God promised Adam that the seed of the woman would defeat sin, death, and Satan, and then promised Abraham that this seed would come through his lineage, through the nation of Israel. Les also notes that all foundations of faith—both the how and the why—rest on what God promised Abraham. The last part of the Abrahamic covenant was that in Abraham all families of the earth would be blessed, primarily through Christ, the seed of the woman coming through the seed of Abraham. This also connects to Romans 11, where Israel rejected everything, and God strips branches from the tree rooted in Abraham and grafts in the Gentiles.