Romans 9:6-9

9:6 It is not as though the word of God had failed. For not all those who are descended from Israel are truly Israel, 9:7 nor are all the children Abraham’s true descendants; rather “through Isaac will your descendants be counted.” 9:8 This means it is not the children of the flesh who are the children of God; rather, the children of promise are counted as descendants. 9:9 For this is what the promise declared: “About a year from now I will return and Sarah will have a son.”