What does the Abrahamic covenant lay the foundation for in the New Testament?
The Abrahamic covenant undergirds the New Testament era: the appearance and earthly ministry of Christ, Israel's rejection of Him, the Church Age following Saul of Tarsus's conversion, and the blessing of all families of the earth through Christ, including Gentiles being grafted in. It is the foundation of all foundations of faith.
Les explains that Genesis promised Adam the seed of the woman would defeat sin, death, and Satan, and then Abraham was given the promise that this seed would come through his lineage, through Israel. That Abrahamic covenant becomes the very foundation of everything coming into the New Testament: the appearance of Christ, His earthly ministry, His rejection by Israel, and the Church Age after the conversion of Saul of Tarsus. Les emphasizes that all foundations of faith—both the how and the why—rest on what God promised Abraham. The covenant's final note, that all families of the earth would be blessed in Abraham, comes primarily through Christ, the seed of the woman through Abraham's seed, and also through what God promised by the Apostle Paul in Romans 11. There, Israel's rejection leads to branches being stripped from the tree rooted in Abraham and Gentiles being grafted in, as Romans 11:15 addresses the casting away of them.