Last spring my congregation finally won its last round of litigation concerning Minnesota's liberalized gun law (yes, liberalized, as in, we're going to tell sherrifs to give permits instead of letting them have discretion, and the state will decide which institutions can be exempt). At the time most states had an automatic exemption for religious institutions, which seems to me to be a fair way to separate church and state on an issue that can be a matter of religious conviction (Mennonites, Quakers and others come to mind).
It's a long, long story, but basically when Minnesota passed a new "personal protection act," it exempted schools, and the State Capitol, but not hospitals, city halls, or churches from onerous "notification" provisions if these institutions wanted to ban firearms. Whereas before we could count on trespass law to work the same way it does for a home (e.g., the congregation as a body decides what the rules about firearms will be within its walls, and how it wants to notify people of those rules), we now had to post state-mandated language at every entrance in big black-and-white letters if we wanted to ban firearms from the premises.
Our congregation decided it would rather decide for itself which words of peace to offer those who enter, thank you very much, so our sign read, "Blessed are the peacemakers. Firearms are prohibited on these premises." We sued the state on the basis of religious freedom, and won every round in court, though it took five years. (All the legal work was pro bono, done by a member of the congregation, so no, we weren't spending our members' offerings on this).
I'm saddened to see that the gun lobby in Arkansas is pressing to remove a ban on guns in houses of worship. I don't know the details, but it seems highly problematic to make a blanket judgment on this. If some churches choose to allow it fine. But the state has no compelling interest in making a religious community allow weapons -- except a police officer's -- on its premises.