Romans 9:7
“Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.”
Whose are the fathers, and of whom as concerning the flesh Christ came, who is over all, God blessed for ever. Amen.
Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:
Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.
That is, They which are the children of the flesh, these are not the children of God: but the children of the promise are counted for the seed.
For this is the word of promise, At this time will I come, and Sara shall have a son.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Related Verses
“That is, They which are the children of the flesh, these are not the children of God: but the children of the promise are counted for the seed.”
“Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:”
“Know ye therefore that they which are of faith, the same are the children of Abraham.”
“And it shall come to pass, that in the place where it was said unto them, Ye are not my people; there shall they be called the children of the living God.”
“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.”