Romans 4:2-5
4:2 For if Abraham was declared righteous by the works of the law, he has something to boast about – but not before God.
4:3 For what does the scripture say? “Abraham believed God, and it was credited to him as righteousness.”
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.