(And I think of C.S. Lewis as a "secret Catholic" even though he was Anglican. I wonder if he would have converted had he lived a few years longer).
Now at the moment when a man feels real guilt—moments too rare in our lives—all these blasphemies vanish away. Much, we may feel, can be excused to human infirmities, but not this—this incredibly mean and ugly action which none of our friends would have done, which even such a thorough-going little rotter as X would have been ashamed of, which we would not for the world allow to be published. At such a moment, we really do know that our character, as revealed in this action, is, and ought to be, hateful to all good men, and, if there are powers above men, to them. A God who did not regard this with unappeasable distaste would not be a good being. We cannot even wish for such a God—it is like wishing that every nose in the universe were abolished, that smell of hay or roses or the sea should never again delight any creature, because our own breath happens to stink.
When we merely say that we are bad, the ‘wrath’ of God seems a barbarous doctrine; as soon as we perceive our badness, it appears inevitable, a mere corollary of God’s goodness. To keep ever before us the insight derived from such a moment as I have been describing, to learn to detect the same real inexcusable corruption under more and more of its complex disguises, is therefore indispensable to a real understanding the Christian faith. This is not, of course, a new doctrine. I am attempting nothing very splendid in this chapter. I am merely trying to get to my reader (and, still more, myself) over a pons asinorum—to take the first step out of fools’ paradise and utter illusion.
--C.S. Lewis, The Problem of Pain