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

For if they that are of the law are heirs, faith is made void, and the promise is made of none effect:

For this cause it is of faith, that it may be according to grace; to the end that the promise may be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham, who is the father of us all

yet, looking unto the promise of God, he wavered not through unbelief, but waxed strong through faith, giving glory to God,

That is, it is not the children of the flesh that are children of God; but the children of the promise are reckoned for a seed.

For this is a word of promise, According to this season will I come, and Sarah shall have a son.