I have about a dozen reasons for not displaying the American OR the misnamed "Christian" flag in the Church building -- and I mean anywhere in the Church building. But I accidentally ran across an Orthodox priest's explanation of why he doesn't allow flag-draped coffins to be processed in for funerals, and I think it is subtly rich and profound. He says,
As I once explained to a military honor guard accompanying a flag-draped casket, "At the church door we remove the flag of state and cover the casket with the pall of the Church. You are about to enter a foreign embassy representing Jesus Christ, who is King over all kings and Lord over all lords, at whose Name every knee will one day bow. As you know, no flag of another state is ever displayed inside a foreign embassy." They understood perfectly.
It seems positively Hauerwasian in its ecclesiology: The Church is the Kingdom of God; we brook no pretenders to the throne, and neither do we tolerate the banners or flag of any such pretender. It will be a sign that the Church is regaining some of her sense of dignity and gravitas when saying such a thing -- either in the priest's words or in mine -- requires no elucidation. Better: when such sentiments are greeted with "well, duh."
You may read the entire post here.