As a non-religious person, I find the indignation about the idea of turning one flavor of house of worship to the god of Abraham into another flavor of house of worship to the god of Abraham to be pretty amusing. And when it happens, it seems so spiteful! Last year I saw the Mosque-Cathedral of Cordoba, and I was struck that the Catholics seemed to be stuffing figurative art _everywhere_, and I guessed it was partly to thumb their noses at the Muslims.

My understanding is that: (a) the three big Abrahamic religions all place the most emphasis on worshiping as a congregation on different days and (b) among each group, a minority of people who identify with the label actually go to worship with a congregation regularly. Would it really be _so_ bad if you had one big fancy palace which switched from hosting Muslims on Friday, Jews on Saturday, Christians on Sunday and could be a museum / community space / charity space Mon-Thurs?

With that view it can get even more amusing when you consider that it was first conquered by the latin empire during the 4th crusade and converted into a catholic church, and then back into an orthodox church about 60 years after, and then finally into a mosque about 200 years after!

As for an interfaith building, it's an interesting thought. There might be issues with ceremonies such as weddings, funerals, and events. There is the Abrahamic Family House in Abu Dhabi, but it's not a single building. I thought something like this might exist in Jerusalem, but I couldn't find any..

Meditation rooms in many airports have a shared sacred space concept. They are often hard to find, but a practical example of cooperation and coexistence.

The Cathedral of Cordoba was a church (Arianism branch of Christianity) before the Muslims converted it to a mosque.

The Visigoth Kingdom was completely wiped out by Muslim invaders.

> As a non-religious person, I find the indignation about the idea of turning one flavor of house of worship to the god of Abraham into another flavor of house of worship to the god of Abraham to be pretty amusing.

It didn't happen by some committee decision, but mostly by killing everybody involved with the old version. That's an important detail.