Romans 4:13

4:13 For the promise to Abraham or to his descendants that he would inherit the world was not fulfilled through the law, but through the righteousness that comes by faith.

Romans 4:16

4:16 For this reason it is by faith so that it may be by grace, with the result that the promise may be certain to all the descendants – not only to those who are under the law, but also to those who have the faith of Abraham, who is the father of us all

Romans 4:18

4:18 Against hope Abraham believed in hope with the result that he became the father of many nations according to the pronouncement, “so will your descendants be.”