Romans 4:4-5

4:4 Now to the one who works, his pay is not credited due to grace but due to obligation. 4:5 But to the one who does not work, but believes in the one who declares the ungodly righteous, his faith is credited as righteousness.

Romans 4:14

4:14 For if they become heirs by the law, faith is empty and the promise is nullified.

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