Augustine of Hippo — as excerpted in the Catena Aurea on John 3:19-21

“(Tr. xii. 13, 14) But if God hath discovered all men’s works to be evil, how is it that any have done the truth, and come to the light, i. e. to Christ? Now what He saith is, that they loved darkness rather than light; He lays the stress upon that. Many have loved their sins, many have confessed them. God accuseth thy sins; if thou accuse them too, thou art joined to God. Thou must hate thine own work, and love the work of God in thee. The beginning of good works, is the confession of evil works, and then thou doest the truth: not soothing, not flattering thyself. And thou art come to the light, because this very sin in thee, which displeaseth thee, would not displease thee, did not God shine upon thee, and His truth shew it unto thee. And let those even who have sinned only by word or thought, or who have only exceeded in things allowable, do the truth, by making confession, and come to the light by performing good works. For little sins, if suffered to accumulate, become mortal. Little drops swell the river: little grains of sand become an heap, which presses and weighs down. The sea coming in by little and little, unless it be pumped out, sinks the vessel. And what is to pump out, but by good works, mourning, fasting, giving and forgiving, to provide against our sins overwhelming us?”