Sinners think that their good deeds commend them to God. Point out that this is how God sees their good deeds (literally, as filthy menstrual cloths)—so imagine how God views their sins. To convince a sinner that his self-righteousness is an offense to a holy God, apply the moral Law to the conscience. For the biblical use of the Law, see Mark 10:17–19; Rom. 2:21–24; 3:19,20; 7:7,13; Gal. 3:24; 1 Tim. 1:8–10. See also Luke 16:15.
“The most damnable and pernicious heresy that has ever plagued the mind of man is that somehow he can make himself good enough to deserve to live forever with an all-holy God.” Martin Luther
Isaiah 64:6 But we are all like an unclean thing, And all our righteousnesses are like filthy rags; We all fade as a leaf, And our iniquities, like the wind, Have taken us away.