What Baha’u’llah has done is build a basis of unity on the essence of religion from the original, discarding the add on content by religious leaders making it very easy to accept all religions.
Maybe some interpretations are questionable, but you take a religion like Christianity, Baha'is disagree with a lot of teachings that are right there in the pages of their Scriptures.
Again, if you want to say that the NT was written by men and that it was their interpretation of things that Jesus said, then I'd agree. Plus, we are counting on them to even know what Jesus said and did. How do we know they weren't embellishing the stories and making things up?
But instead, Baha'is try to say that stories like the raising of Lazurus and the resurrection of Jesus were symbolic. Why not just plain old made-up fiction?
And most all of us have been told by Christians that we need Jesus to be forgiven of our sins... that we've inherited a sin nature from Adam. And that we are being deceived by Satan if we don't believe. Where does all that come from? That's straight out of the NT.
If it's not true, then get rid of it. But that's not what you're saying. You're saying to keep the Scriptures of Christianity and the other religions.... read them, learn from them... just don't believe them as interpreted by the people in that religion. Interpret them according to how the Baha'i Faith interprets them.
Like again with Christianity and the NT, there is no Satan, no hell, no inherited sin, no resurrection, which leaves us with no need for Jesus to have given his life. There was no need of a sacrifice. He didn't have to die to pay the penalty for our sins. We are not going to hell if we reject all those beliefs.
You are leaving only a few meaningful things from the NT, the main one being "Love your neighbor as yourself." And that's not unique to Christianity. Because it is common to all the major religions, Baha'is take that one thing to say, "See, they all teach the same things." No, they are all over the place with beliefs about everything. Dump those old beliefs? Sure, I'm fine with believing most of the things were myth.