Mono = ONE.
Three does NOT equal one.
It's pretty simple, really.
As an Orthodox Jew, I believe--and am taught--that Islam is a monotheistic religion, and that Christianity is not. Now, since I'm Orthodox, I'm a little stricter than other Jews. But my rabbi advises that I should not--EVER--for any reason--enter a church's sanctuary, because it is a place of idol worship.
In a pinch, I COULD go into a mosque.
This is something that really upsets Christians, when they hear it. And I'm sorry--I respect many Christians. Then again, I respect many Hindus, and could not enter a Hindu temple.
Again, 3 doesn't equal 1.