Something important to consider is that you are looking at the continuation of Judaism after the fact. If you were to go back 2,000 years, and try to predict in advance what would happen, it would be reasonable to expect that a society of some sort would survive, though predicting exactly which society of the many available would probably be beyond you.
So yes, Judaism survived against all odds, but the survival of any one particular society would be against all odds. A world without God would likely have some society, and which particular society would be up to a roll of the dice.
Imagine a group of 10 people, and some sort of system which would cause 9 of them, randomly chosen, to die before tomorrow. The 1 would survive because the rules of the system allowed for a survivor, not because of an inherent quality of that one person. In the same way, our world allows for some surviving cultures, though which culture survived is based significantly on luck, not just their deity.
Additionally, China surviving, by your reasoning, would provide evidence that China's religious beliefs are true. In fact, as they're thriving far more than Judaism (by number of people), your reasoning indicates that a shift towards their religious beliefs would be appropriate.
Also worth asking: in a world without a God would you expect to see religion? With many contradictory religions, most would have to have sprung up despite being wrong. It would only be a small shift to suppose that all of them may be.
You probably won't see this since it's six years old, but just in case, why do you think such a long time? A significant portion of people who are in the AI field give a much closer number, and while predicting the future isn't exact, 500 years is a pretty big difference from the numbers I've most often seen.