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

For if they who are of the law are heirs, faith is made void, and the promise of no effect.

Therefore it is of faith, that it might be of grace, that the promise might be firm to all the seed; not only to that which is of the law, but to that also which is of the faith of Abraham, who is the father of us all, (As it is written,

He staggered not at the promise of God through unbelief, but was strengthened in faith, giving glory to God,

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

For this is the word of the promise, At this time I will come, and Sarah shall have a son.