Romans 4:18-21

He believed, hoping against hope, so that he became the father of many nations according to what had been spoken: So will your descendants be. He considered his own body to be already dead (since he was about 100 years old) and also considered the deadness of Sarah’s womb, without weakening in the faith. He did not waver in unbelief at God’s promise but was strengthened in his faith and gave glory to God, because he was fully convinced that what He had promised He was also able to perform.