For the promise made to Abraham, or to his seed, that he should be heir of the world, was not by the law, but by the righteousness of faith:

for if they only that are of the law be heirs, faith is made useless, and the promise is become of no effect.

And therefore it is of faith, that it might be by grace, that so the promise might be sure to all the seed; not to that only which is of the law, but also to that which is of the faith of Abraham, who is the father of us all,

He hesitated not at the promise of God through unbelief: but was strong in faith, giving glory to God,

Nor because they are the seed of Abraham, are they all children of promise: but "in Isaac shall thy seed be called."

That is, not the children of the flesh are the children of God, but the children of the promise are accounted for the seed.

For this is the word of the promise, "According to this time will I come, and Sarah shall have a son:"