A cover for unrighteousness
In the meantime, what we are afraid of is this, lest any should use the phrase "the righteousness of Christ," or "the righteousness of Christ is imputed to me," as a cover for his unrighteousness. We have known this done a thousand times. A man has been reproved, suppose, for drunkenness. "Oh," he said, "I pretend to no righteousness of my own. Christ is my righteousness." Another has been told that the extortioner, the unjust, shall not inherit the kingdom of God (1 Corinthians 6:9-10). He replies with all assurance, "I am unjust in myself, but I have a spotless righteousness in Christ." And thus, though a man is as far from the practice as from the tempers of a Christian, though he neither has the mind which was in Christ (Philippians 2:5), nor in any respect walks as he walked (1 John 2:6), yet he has armor of proof against all conviction, in what he calls the righteousness of Christ.
1771 text
19. In the mean time, what we are afraid of is this; lest any should use the phrase, “The righteousness of Christ,” or, “The righteousness of Christ is imputed to me,” as a cover for his unrighteousness. We have known this done a thousand times. A man has been reproved, suppose, for drunkenness. “O, said he, I pretend to no righteousness of my own: Christ is my righteousness.” Another has been told, that the extortioner, the unjust, shall not inherit the kingdom of God. He replies with all assurance, “I am unjust in myself, but I have a spotless righteousness in Christ.” And thus though a man be as far from the practice as from the tempers of a Christian, though he neither has the mind which was in Christ, nor in any respect walks as he walked, yet he has armour of proof against all conviction, in what he calls the righteousness of Christ.