Romans 4:19-22

Without becoming weak in faith he contemplated his own body, now as good as dead since he was about a hundred years old, and the deadness of Sarah’s womb; yet, with respect to the promise of God, he did not waver in unbelief but grew strong in faith, giving glory to God, and being fully assured that what God had promised, He was able also to perform. Therefore IT WAS ALSO CREDITED TO HIM AS RIGHTEOUSNESS.