The use of conviction is not to punish a man for his sins; nor is it to make him any better. The devils in hell have been under awful conviction for a long time, and not one of them is any better. The sole object of conviction is to shut up the soul to the faith of Jesus. The sole object of conviction is to bring the sinner to accept salvation by atoning blood.
W. S. Plumer, in William R. Moody, The Life of Dwight L. Moody, 269–70.
That’s the trouble with moralism/legalism, it does not understand the use of the law to drive us to despair of our ability to be justified by our efforts to obey it. It presents obedience to the law as something we can do as our part in order to be accepted by God. In doing so it condemns us, because it brings us under obligation to obey the whole law. Gal. 5:4