One big problem is that the unbeliever is looking at himself through his own eyes instead of the holy eyes of God, the Judge. In the end, our opinion of ourselves is not the issue. God is perfect in love, holiness, justice, grace, mercy, wrath. The unbeliever justifies himself and does not understand the issues at all. God is a responsible Moral Governor of the universe.
Genesis 18:25 The Judge of all the earth will do the right thing with sinner and saint. If there was another way, God would have revealed it.
The gospel deals with God, man, Christ, repentance-faith. It is the power of God and needed by all men (Rom. 1:16). We can deny cancer, sin, death, hell, etc., but the reality will not change. Gravity will apply whether we think it does or not (test it by jumping off a bridge).