I wasn't sure the best place to post this...
In the New Member Meet & Greet last night, Cassius asked what triggered me to abandon Catholicism, and then later asked if I had any book recommendations. I didn't have good answers at the time, but I remembered something later.
Probably the book that pushed me over the edge from Catholic-by-inertia was Thomas Paine's The Age of Reason.
After that, I also spent some time reading textual criticism of the Bible, I particularly recall Albert Schweitzer's The Quest of the Historical Jesus. But also more recent works in that area since the discovery of the Dead Sea scrolls.
Those aren't Epicurean (obviously). And Paine is pushing Deism.
And I wouldn't recommend them to committed Christians (to avoid making enemies!).
But for people who are fed up with Christianity but just can't bring themselves to reject it completely, maybe those would be useful.