Romans 4:18-22

In hope beyond hope, he trusted that he would become the father of many nations according to what was spoken—“So shall your descendants be.” And without becoming weak in faith, he considered his own body—as good as dead, since he was already a hundred years old—and the deadness of Sarah’s womb. Yet he did not waver in unbelief concerning the promise of God. Rather, he was strengthened in faith, giving glory to God. He was fully convinced that what God has promised, He also is able to do. That is why “it was credited to him as righteousness.”