I'm having a hard time understanding the following sentence because of by example:
This is because religions could never have got started, let alone thrived, unless for the influence of men as fanatical as Moses or Muhammad or Joseph Kony, while charity and relief work, while they may appeal to tenderhearted believers, are the inheritors of modernism and the Enlightenment. Before that, religion was spread not by example but as an auxiliary to the more old-fashioned methods of holy war and imperialism.
I'm not sure if I should treat it as in lead by example. I don't think so but that's the closest thing I can come up with.
Assuming that it's like in lead by example, what I understand from the sentence is that before the Enlightenment, religion was spread not in a way to be looked up to/modeled on etc. but in a way that is auxiliary to ….