NOTES for Act 3:25
The apostle Peter addresses the descendants of Abraham, reminding them of the covenant and showing that the time has come for the fulfillment of God's promise, the blessing of all the families of the earth through the "seed of Abraham," through Jesus Christ. It is clear that we can easily count ourselves among these "families of the earth" who have received the grace of salvation in Christ Jesus. But, as the New Testament points out many times, we are also descendants of Abraham, if not according to the flesh, then according to the spirit, because faith stands at the center of our life, the very faith that Abraham showed and that God counted to him as righteousness. So Abraham is the "father of all believers," and this means that we turn out to be heirs of the prophecies, revelations, and promises that God gave to the sons of Abraham. But then everything Scripture says about the responsibility of God's people before their God applies to us as well.