The lost do not consider that they are disobedient and have sinned against a holy God innumerable times. By judging themselves against man’s standards, they come up reasonably clean. Adolf Hitler’s life, for instance, makes most of us look almost pure.
However, when we use the Law of God as our measure, we see that we are not as clean as we like to think. We need to apply the spiritual nature of God’s Law to the conscience of sinners so they can see that their own righteousnesses are as filthy rags in the sight of a holy God (see Isaiah 64:6).
“God never clothes men until He has first stripped them, nor does He quicken them by the gospel till first they are slain by the Law. When you meet with persons in whom there is no trace of conviction of sin, you may be quite sure that they have not been wrought upon by the Holy Spirit; for ‘when He is come, He will reprove the world of sin, and of righteousness, and of judgment.’” Charles Spurgeon
Isaiah 42:24 Who gave Jacob for plunder, and Israel to the robbers? Was it not the Lord, He against whom we have sinned? For they would not walk in His ways, Nor were they obedient to His law.