Romans 9:8-12

This means that Abraham’s physical descendants are not necessarily children of God. Only the children of the promise are considered to be Abraham’s children. For God had promised, “I will return about this time next year, and Sarah will have a son.” This son was our ancestor Isaac. When he married Rebekah, she gave birth to twins. But before they were born, before they had done anything good or bad, she received a message from God. (This message shows that God chooses people according to his own purposes; he calls people, but not according to their good or bad works.) She was told, “Your older son will serve your younger son.”