The covenant blessings actually begin in Gen. 3:15, when God promises that a "seed" will come from Eve and that the seed will cause a fatal wound to the seed of the serpent. Two important aspects should be noted concerning what we call the "Adamic Covenant" (a fancy way of saying the Covenant God made with Adam through Eve). First, it is unconditional, that is only God Himself is required to make sure it is fulfilled. And secondly, it is made with mankind in particular, in that Adam and Eve were the first of all humanity, not a particular nation or ethnicity.
Gen. 12:1-3 (the Abrahamic Covenant) another great covenant is woven into the tapestry. In this promise we learn that Abraham is not the seed, but through his seed, that is his descendants which are represented by seed, all people will be blessed. This is a key point, because it is the foundation of all the promises we inherit when we, as Gentiles, profess faith in The Seed (who we later learn is the Messiah, Jesus Christ). Although Abraham is childless when he receives this promise from God, we can follow the fulfillment of this promise and its continued fulfillment through the story of Isaac (Gen. 15:1-6; Gen. 21; Gen. 26:1-5; Gen. 26:24) and Jacob (Gen. 28:12-16). This promise is repeated several times throughout the final chapters of Genesis, the most notable is Gen. 35:9-13 where Jacob's name is changed to Israel and the promise moves from a person to a nation. The covenant remains "unconditional" in that God will be the one to bring it to pass. A nation is a large entity to pull one promise out of, especially when that nation is formed by not 1, but 12 sons! So the conduit of the promised Seed moves to a particular tribe, Judah (Gen. 49:8-12).
The thread of this promise will not emerge again until 2 Sam. 7:8-16 (the Davidic Covenant), when a descendant of Judah, takes the throne. Here God makes an astounding promise to David, Judah's descendant, that unlike other earthly kings, David's descendant will sit on the throne forever. Humanly speaking this is impossible. And just to confirm that the fulfillment of this promise is not dependent on human initiative both David, and his heir apparent Solomon, die as do all the generations after them. So within the eras of Israel's history the promise of The Seed submerges once again and it does not resurface until many generations later.
Now we'll take a great leap forward and land in Luke 3:23-38 which concerns the genealogy of Jesus Christ. Luke's record is very careful to include not only David's lineage, but it continues to go all the way back to Abraham AND Adam. Luke wants you to understand that God has always intended the promise of Gen. 3:15 to be a promise made for everyone. It was a promise that was made when Israel as a nation was only a glimmer in God's eye, so the promise is not particular to one people group, but all inclusive. Luke not only makes this one of the themes of his Gospel, it is also the main theme of the Book of Acts which was also written by him. Later on, when Paul writes to the Romans (a group of believers composed mainly of Gentiles) he goes to great lengths to call attention to the all-inclusiveness of the Gospel and its blessings to all who believe it. Romans chapter 4 is a monumental tribute to Abraham's descendants, not only the ones in his "fleshly" family tree (his physical descendants) but those in his "spiritual" family tree; those of us who exhibit his spiritual attributes of faith. It is a fitting conclusion to the thread of the Promised Seed and the Big Picture of salvation which is woven in the Covenant tapestry of Scripture. There is The Promised Seed (Jesus), but also a harvest of seed who believe, and that's you and me!
Ann H. LeFevre, M. Div.
https://www.annhlefevre.com; Olivetreeann@mail.com; https://www.linkedin.com/in/annhlefevre; https://www.facebook.com/ann.h.lefevre