“It is not as though the word of God had failed. For not all those who are descended from Israel are truly Israel,nor are all the children Abraham’s true descendants; rather “through Isaac will your descendants be counted.”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.” (Romans 9:6–8) (NET)
“Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.” (Galatians 3:16) (KJV 1900)
“And if ye be Christ’s, then are ye Abraham’s seed, and heirs according to the promise.” (Galatians 3:29) (KJV 1900)