I should add that I do know of cases - more than a few, in fact - where someone who was atheist, agnostic, or merely nonpracticing has individually come to what we could call a "crisis of non-faith," and become more interested in religion, thus seeking out a Christian friend or acquiantance in order to better learn what it is to be a Christian. I just don't know of any cases where a large group of people all had crises at the same time and came to that conclusion. Nor of a group of people all deciding at once to read a book of a religion they do not follow.

Unless you count the Kama Sutra - is that a religious text or purely secular?