Georgia has banned guns in church and it was challenged. Issue went up to SCOTUS after the ban was supported at a lower federal level. SCOTUS passed on the issue.
This annoys me. The rationale for a gun ban should be based on some criterion that makes sense:
1. Technical - no gun by the MRI - BOOM!
2. Private property bans (I disagree with this by the way) that has some basis in rights and law.
However, the mandatory banning in religious institutions is based not on some direct measure of safety or rights but in a mistaken emotional belief that such places are sacred or whatever. You insult whatever you believe in by having a gun.
Well, the deities can take care of themselves. If they don't want guns, let them speak.
The state cannot set the conditions for worship if it is not a direct issue of safety. Your opinion of sacred cannot tell a religious institution how to worship. Can the ceremonial knives of Sikhs be banned in GA?
These bans are clearly unconstitutional infringements on the conditions of religious practice. Shame of on SCOTUS. If Scalia thinks this is reasonable, well - then he is not.