When you leave a man alone with his Bible and the Holy Ghost inspires him, he's going to be a Catholic one way or another, even though he knows nothing about the visible church. His kind of Christianity may not be socially desirable, but will be real in the sight of God.

The Habit of Being: Letters of Flannery O'Connor (ed. Macmillan, 1988) - ISBN: 9781466829015