Romans 9:7-9

New Century Version

⁷ and only some of Abraham’s^[a] descendants are true children of Abraham. But God said to Abraham: “The descendants I promised you will be from Isaac.”^{[b] 8} This means that not all of Abraham’s descendants are God’s true children. Abraham’s true children are those who become God’s children because of the promise God made to Abraham. ⁹ God’s promise to Abraham was this: “At the right time I will return, and Sarah will have a son.”^[c]