Now as to answer your "real question". The ancient Jewish faith was flawed but they were the chosen nation. No doubt surrounding nations thought them crazy and they probably warned their young ones of pitfalls. So the comparison to Christendom could very well fit today.
Here's the problem. If all religions are flawed, this reasoning will prevent people from changing beliefs.
Someone who's born a Mormon, for instance, would not make a change to the JWs because while his religion might be flawed, so are the Witnesses. It's the "where shall we go?" fallacy. Absent evidence of a lack of flaws in another group, the person will stay in their current group assuming it's the "chosen religion."
And it assumes there is such a thing as a "God's people" or a "chosen nation" to begin with.
Going back to your example. Maybe the ancient Jews made up a religion just like every ancient group of peoples did. Maybe Yahweh was just a mythical as Zeus, Krishna or Ra. Maybe the Jews were crazy and the surrounding nations were right to warn their young ones.
Maybe, maybe not. I'm leaning towards the latter.