How does the blessing of all families of the earth come about?
The blessing of all families of the earth comes primarily through Christ, the seed of the woman coming through the seed of Abraham. It is also a result of God's promise in Romans 11, where Israel's rejection leads to Gentiles being grafted into the tree rooted in Abraham.
Les explains that the Abrahamic covenant is the foundation of everything, including the New Testament, Christ's appearance, His earthly ministry, Israel's rejection, and the Church Age after the conversion of Saul of Tarsus. The promise that in Abraham all families of the earth would be blessed is fulfilled primarily through Christ, the seed of the woman coming through Abraham's lineage. It also results from what God promised through the Apostle Paul in Romans 11, where Israel rejected everything, and God will strip the branches from the tree (Israel) rooted in Abraham and graft in the Gentiles. This ties together with Romans 11:15.