Who’s saying the original religion as given by the Founder is wrong? What is being clearly stated is that man made additions which were never part of the original teachings are rejected. The original religion itself rejects the additions. (See Revelation below) Do you see ‘Mary the mother of God’ anywhere in the Bible ? Or the trinity! That’s because they were ‘added’ . But the Beautitudes , the law to love one another and forgive others which Baha’is fully endorse ARE in the original teachings. So please be fair here. We are not rejecting the original teachings Just the added dogmas and interpretations.
Revelation 22:18
For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book:
Let's be fair? How about let's be real. Baha'is believe the Bible, which I think you include the NT with it, is not "wholly" authentic. And I completely understand why Baha'is would say that. It wasn't written by Jesus. Even when it says that it was Jesus speaking... how do we know?
The NT, to me, clearly says Jesus came back to life. So, who has the wrong interpretation? The Baha'is who say that the resurrection was symbolic? Or the Christians that believe and trust what was written? They aren't interpreting anything. They are taking it for what is says.
But then... who picked which gospels and epistles got accepted into the canon of Christian Scriptures? It was the religious leaders that you've said added man-made things in and misinterpreted those writings they decided to make into their Scriptures. Why then believe any of it?
But, as with the other religions, there's some things in the Scriptures that Baha'is need. But there is also lots of things Baha'is don't need nor want.
These "original" teachings are what then? What the Baha'is say they are? That is the problem. Are these friends of yours from the other religions okay with Baha'is believing that all the other religions have man-made doctrines and wrong interpretations?