We have all read the Baha'i quote that says the Bible is not totally authentic. And how could it? Various writers that nobody really knows who they are. Nobody knows if Moses really wrote the first five books. But we do know Jesus wrote nothing. And that every accepted and canonized gospel has variations in it. Then, like in Daniel, when was it really written and who wrote it? If it isn't perfectly accurate, then how can we trust those prophecies in it? But, then can we trust it when it says Daniel's friends were thrown into a furnace and didn't die or even get burned? That certainly isn't true is it?
But, the intent of most religions is generally to give rules to live by. Those rules have changed, progressed, over time. So Baha'is are kind of right. All religions are similar and have progressed when it comes to social laws. But, they have also changed with how they see spiritual things too. And that don't fit with what Baha'is say. One God, no God, many Gods? Incarnations, reincarnations? Devils and demon gods? For me, religion seems like just reasonable guesses at what a spiritual world would be like. And, the laws fit really well into what each culture needed to keep order in their society. And, as society changed, those laws changed. But the easiest thing to do was to say those laws came from a God, so you better obey them. So I almost agree with the Baha'i Faith, just a few minor adjustments in interpretation.