Carrying a gun may not be about theory or odds, but (to avoid making this personal) I'm quite sure the vast majority of those who carry firearms make more dangerous choices than going unarmed every day and ignore the risks. Just one example, those who drink to excess, smoke, are overweight, and/or get no real exercise are far more likely to die of disease caused by that than a 'bad guy' in most areas of the U.S. and certainly the risks are 100s or 1000s of times higher than getting attacked at church.
Or to put this another way, this all started with some incredible idiot at NRA making comments about carrying guns in churches. But I'm 100% positive that same guy would oppose new OSHA regs addressing remote risks in the work place, or EPA issuing new regs for cleaner air that MIGHT save 500 lives per year, but he wants everyone to go armed at church. It only makes sense because he works for the marketing arm of the gun manufacturers and fear sells lots of guns, i.e. he is for addressing remote risks at church with a GUN because his clients sell guns. But if addressing remote risks costs his clients or other interest groups that support the GOP money, I'd bet any amount he'll oppose them, and no one would take the bet on the other side.