Dave Barrry once described his role in a musical group in the following manner: "I am also--and I am not bragging here--the only person who actually knows when the song has started and ended". In a like manner, I shall begin to wax shamelessly abstract, as I am not only the only person who will have the faintest clue as to what I am talking about, but probably one of maybe three who will know that I am talking at all.
God is, by definition, Absolute. Therefore, He is the only standard by which anything can consistently be judged, and all that judgments can do with any integrity is to merely judge how far removed from God something is.
But this is very dangerous. To judge how far removed from the standard something is, you must know where the standard is, which is something that we are by definition incapable of knowing: God is infinite, we are finite. There is therefore an infinite gap between us and the standard, and perhaps a two or three inch gap between us and Hitler (or, if you use the metrical system, none at all. I'm going to college!).
The implications of this are crushing. You see that drug addict? You have no authority with which to despise him. That prostitute? Judge yourself first, hypocrite. You want to point and condemn? The only one that you can end up condemning is yourself, and that right speedily.
The only difference between you and the ones you pity was Grace; the only difference between you and the ones you despise was a Choice, and but for the Grace of God you would have had no choice, and but for the Choice of God, you would have had no Grace.
To quote Lewis: "What will all that chatter and hearsay count? Will you even be able to remember it, when this anaesthetic fog which we call 'nature' or 'the real world' fades away, and the Presence in which you have always stood becomes palpable, immediate, and unavoidable?"
Let us live coram Deo, not coram homo.