What does the New Testament say about the fulfillment of God's promises to Abraham?

In the New Testament, particularly through the writings of Paul, we see that the promises made to Abraham are fulfilled in Christ and extend to all who believe. Romans 9 discusses how not all physical descendants of Abraham are included in the promises; rather, it is the children of promise—those who have faith in Christ—who inherit these blessings. Additionally, in Galatians 3, Paul articulates how believers, both Jew and Gentile, are heirs according to the promise through faith in Jesus. This indicates that God’s plan was always to incorporate a diverse people into His family, showing His mercy and grace across all nations, which is ultimately realized through Christ’s work.