Romans 4:5

But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is reckoned for righteousness. [Let us illustrate our point by the case of a workman. If the workman does all he agreed to do, then his reward or hire is due him, not as a matter of grace or favor, but as a just debt. But if, on the contrary, the workman does not fulfill his agreement at all, but merely believes the promise of his employer that he shall nevertheless be paid, then the hire is not hire at all; it is a mere gift of grace and favor, and not a debt. Now, this latter is the position occupied by Abraham, and by every one that believeth on him that justifieth the ungodly, for their faith is reckoned unto them for the works of the law--those works of righteousness which they promised to do, but never performed. The sentence is very elliptical, the apostle mingling the illustration with its application, in the on-rushing of his thought.]