Romans 4:4,5 - Joseph Benson’s Commentary on the Old and New Testaments

Now to him that worketh All that the law requires; is the reward not reckoned of grace Or mere favour; but of debt It is due to his merit. Not that God can properly and strictly be a debtor to any creature, in respect of communicative justice; but if man had continued in that state of holiness wherein he was made, that he should have been esteemed righteous, and have continued in God's favour and lived, would have been according to the rules of distributive justice. But to him that worketh not In the sense above explained, who can by no means pretend to have wrought all righteousness; but Conscious of his sinfulness and guilt, and of his utter inability to justify himself before God; believeth on him Who, in his great grace, justifieth the ungodly person, when he truly repents and returns to God; his faith is counted Or placed to his account; for righteousness He is graciously accepted, and treated by God as if he were perfectly righteous. Therefore, God's affirming of Abraham that faith was imputed to him for righteousness, plainly shows that he worked not; or, in other words, that he was not justified by works, but by faith only. Hence we see plainly, how groundless that opinion is, that holiness or sanctification is previous to justification. For the sinner, being first convinced of his sin and danger by the Spirit of God, stands trembling before the awful tribunal of divine justice, and has nothing to plead but his own guilt, and the merits of a Mediator. Christ here interposes: justice is satisfied: the sin is remitted, and pardon is applied to the soul by a divine faith, wrought by the Holy Ghost, who then begins the great work of inward satisfaction. Thus God justifies the ungodly, and yet remains just and true to all his attributes. But let none hence presume to continue in sin, for to the impenitent God is a consuming fire.