Romans 4:18

16For this cause it is of faith, that it may be according to grace, to the end that the promise may be sure to all the offspring, not to that only which is of the law, but to that also which is of the faith of Abraham, who is the father of us all.

17As it is written, “I have made you a father of many nations.” This is in the presence of him whom he believed: God, who gives life to the dead, and calls the things that are not, as though they were.

18Against hope, Abraham in hope believed, to the end that he might become a father of many nations, according to that which had been spoken, “So will your offspring be.”

19Without being weakened in faith, he didn’t consider his own body, already having been worn out, (he being about a hundred years old), and the deadness of Sarah’s womb.

20Yet, looking to the promise of God, he didn’t waver through unbelief, but grew strong through faith, giving glory to God,