Rom 4:17-18, 17 as it is written, “I have made you the father of many nations”—in the presence of the God in whom he believed, who gives life to the dead and calls into existence the things that do not exist. 18 In hope he believed against hope, that he should become the father of many nations, as he had been told, “So shall your offspring be.”
To take God at His word when things are still bearable is one thing, to take Him at His word when all is considered dead is another thing. Paul describes the faith of Abraham who took God at His word for a son. Through his offspring Isaac, God was to make him a great nation. If Abraham was still young with his wife, they would be in the bracket of possibilities and great chance percentage wise to have children. At this point he was 75 years old and his wife as Heb 11:11 reads was past the age of conceiving. Their windows by the laws of nature had closed, but God still fulfilled after another 25 years had passed.
Even with the start and the length of time, Abraham believed God who “… give life to the dead and calls into existence the things that do not exist.” He hoped against all hope and waited patiently however long it took. Abraham teaches us that God defies the laws of nature and does what He promises if we too have hope against all hopes because of our confidence in His ability. Faith that works rests on God’s promises despite the realities.