"Therefore it is of faith that it might be according to grace, so that the promise might be sure to all the seed, not only to those who are of the law, but also to those who are of the faith of Abraham, who is the father of us all (as it is written, "I have made you a father of many nations") in the presence of Him whom he believed - God, who gives life to the dead and calls those things which do not exist as though they did."
Romans 4:16-17
God calls things that are not as though they were.
That's how the heavens and the earth got here in the first place. Once they were not, then they were because God spoke them into existence.
That's how God works. He speaks and expects His Word to be fulfilled.
That's what we are to do, speak God's Word and expect it to be fulfilled.