Ah the esoteric interests,
I find that this thread is an excellent observation. For example, myself I was born in Roman Catholicism, and raised that way, albeit not in a very staunch fashion. My values are very Christian, and I find my faith keeps me strong.
However, I have been curious as well and have read, and actually participate which would make me very Un-Catholic. What keeps me strong again is my faith.
You can see a resurgence of beliefs that question Christianity. The belief in a Female deity, as in the story of Christ, Mary Magdalene, and the Holy Grail is but one example.
Holy Blood, Holy Grail by authors Michael Baigent, Richard Leigh, and Henry Lincoln explored this in detail and was an explosive book when released in the early '80s. It's popularity resurged recently with a release of another popular work, albeit fiction, The Davinci Code by Dan Brown. I have read both, and I advise reading Holy Blodd first!
As for secrets, and soceties that keep them, short of being within that circle there is no way of knowing exactly what is practiced. Picking up a book is like looking at the menu at a resteraunt. Until you bite in to the real thing, it is still a description. Masonry, touched on by the books I have mentioned, has been written time and time again by so called "Experts" in the field who have never spent so much as a meeting within the lodge. Yet have published volumes of the secrets of the level.
Either way, a good thread and this is one I hope grows in to a long, friendly discussion.
fy
tess