Today, I underlined this:
I don't think you should write something as long as a novel around anything that is not of the gravest concern to you and everybody else and for me this is always the conflict between a attraction for the Holy and the disbelief in it that we breathe in with the air of the times. It's hard to believe always but more so in the world we live in now... I can't allow any of my characters, in a novel anyway, to stop in some halfway position. This doubtless comes of a Catholic education and a Catholic sense of history--everything works toward its true end or away from it, everything is ultimately saved or lost. Haze is saved by virtue of having wise blood; it's too wise for him ultimately to deny having wise blood; it's too wise for him ultimately to deny Christ. Wise blood has to be these people's means of grace--they have no sacraments. The religion of the South is a do-it-yourself religion, something which I as a Catholic find painful and touching and grimly comic. It's full of unconscious pride that lands them in all sorts of ridiculous religious predicaments. They have nothing to correct their practical heresies and so they work them out dramatically. If this were merely comic to me, it would be no good, but I accept the same fundamental doctrines of sin and redemption and judgment that they do.
... Haze knows what the choice is and the Misfit knows what the choice is--either throw away everything and follow Him or enjoy yourself by doing some meanness to somebody, and in the end there's no real pleasure in life, not even in meanness. I can fancy a character like the Misfit being redeemable, but a character like Mr. Shiftlet as being unredeemable. (letter to John Hawkes, Sept. 13, 1959)
It is the part about the "half-way" position which grabbed me, but also the "self-made" religion without sacraments.