In connection with the previous post, I saw fit to post this excellent and concise comment by our own AlexH:
The truth of Judaism is based on Divine revelation in the presence of an entire nation of several millions, something that no other religion is able - or has ever tried - to claim, and which is pretty well impossible to falsify after the fact. (If you try to convince someone that his ancestors experienced some transformative experience, he might well counter by asking why, if it was that important, his parents never mentioned it to him before.)
