Romans 4:2, 13-15

For if Abraham were justified by works, he hath whereof to glory; but not before God.

For the promise, that he should be the heir of the world, was not to Abraham, or to his seed, through the law, but through the righteousness of faith. For if they which are of the law be heirs, faith is made void, and the promise made of none effect: because the law worketh wrath: for where no law is, there is no transgression.