The reason why so many people leave the Catholic Church is not because they lost their faith, but because they never had it in the first place. They are not raised to have any faith. They are trained to think of Catholicism as a set of rational propositions combined with a set of rules which one must follow. They think doctrines can be reasoned out by anyone, and should be reasoned out, just as one reasons out a mathematical proof (and so if they can’t do it themselves, they give up on the doctrine). What is left, then, is a set of rules that one has to live out one’s life. And isn’t that what we see with so many people – all they offer to others are rules, rules, and more rules. “Don’t do this, don’t do that”? No positive, holistic approach can be found in how they deal with their faith, for, in the end, there is no faith. Because of them, and how often they tend to be among the most vocal of Catholics, is there any wonder that people think this is what Catholicism (and religion) is about? Flannery O’Connor met with a young woman who left the Church because of this:
The other thing concerns a girl I am writing to who is a lapsed Catholic. She says she found that instead of ‘make straight the way,’ it was ‘make tight the straight jacket,’ and that her family was very strict about trifles and treated the negroes terrible, etc., etc. A typical Catholic family, I gather. Anyway, apparently the straw that broke the camel’s back with her was when a priest told her that it was a mortal sin to eat meat on Friday. She is real confused and I am trying to give her suggestions about reading some people like Maritain as she obviously never read anything but the Do-Nots.
— Flannery O’Connor, Letter To Father James H. McCown, Dec 29, 1957 in O’Connor: Collected Works. Ed. Sally Fitzgerald (New York: Library of America, 1988), 1058.