Maybe you could explain the verses below to help me see where I'm wrong. The childern of the flesh ARE NOT the children of God. I take that to mean FLESH descendants aren't the children of God and ARE NOT counted for the seed.
Romans 9:6-8 KJV
Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:
[7] Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.
[8] 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.