The Protestant church where I grew up had two flags displayed at the front of the sanctuary: The flag of our church, and the U.S. flag on the other side. I always wondered why the U.S. flag was on display there, as in my mind it had nothing to do with religion.
My impression (although memory is hazy) is that this is common, at least in Protestant churches in the U.S.
Is this as common as I think it is? Do other religions do the same thing in the U.S. (Catholic, Jewish, any others)? Is this done abroad? When and why did this practice originate?