(see his initial post to this discussion for the full contents)
There's a joke, not from me:
Suppose there is the Red Church, the Blue Church and the Yellow Church. Now, the Blue Church and Yellow Church decide to unite. How many churches are left?
Four: The Red Church, the United Church, the Blue Church and the Yellow Church...
It can happen no other way. Embracing the Oneness of humanity with the knowledge we are guided by the One same God, the God of Noah, Abraham, Krishna, Moses, Zoroaster, Buddha, Jesus Christ, Muhammad, the Bab and Baha'u'llah.
There have been other prophets and other people who claimed to be a prophet. Even if we read all scriptures, we would not come to the same conclusion - hermeneutical aspects, the way we think, how we feel, where we come from, whom we meet and what we experience will result in different thoughts and different practice.
The key to this unity is our ability to throw away all the prejudices we have built, race prejudices, gender prejudices and religious prejudices, prejudices resulting from our attachment to a material world, above our ability to embrace the Oneness given of God via all the Messengers and the 'Books' (Word) they have given.
If we try to meet without prejudice, as humans, we will have the openeness at least to come to a respectful unity in diversity. I think, it will fail to unite all people under one religion - even if there is one God.
how it is written in the Quran (5:47-48):
So let the people of the Gospel rule according to what God revealed in it. Those who do not rule according to what God revealed are the sinners. And We revealed to you the Book, with truth, confirming the Scripture that preceded it, and superseding it. So judge between them according to what God revealed, and do not follow their desires if they differ from the truth that has come to you. For each of you We have assigned a law and a method. Had God willed, He could have made you a single nation, but He tests you through what He has given you. So compete in righteousness. To God is your return, all of you; then He will inform you of what you had disputed.