All the definitions agree that it has to do with an "attitude or belief that one's own opinions, however irrational or ignant, are superior to the other irrational and ignant opinions ofothers".
When it comes to "religion", they are all pretty formal, and the believers hold to "truths" derived from long term observations or revelations.
Religious truths, to any believer of whatever religion, are NOT irrational, nor ignant, nor are they mere opinions.
When you accuse religious believers, of any kind, of being bigots you are attacking a body of truths ~ and the normal human reaction to that is going to be much more violent and assertive than you would get for simply criticizing their opinions, irrational or ignant as they may be.
We don't need a "be kind to' Mormons, Catholics, Baptists, Anabaptists, Buddhists, Hindus, Tao, or snakehandling approach ~ something more like total avoidance of the incorrect term 'bigot" or its derivatives would probably be OK.
If a specific practice of the "other' is particularly noisome to you maybe you should go after it. The people who think you can command God with a word don't like Mormon post mortem baptism ~ and they've gone after the Mormon's on that point. I've gone after the "command God' folks on that point ~ but with a reason.
Simply accusing them of mindless evil bigotry just wouldn't get to the point because otherwise we like the way the Mormons cut their lawns, and the "command God' folks park in their driveways and keep the kids in.
I think we could all keep our fingers off the trigger words in any religious discussion simply by remembering the 'other guys' (or for any of you mind-numbed, knee-jerk, robot-like leftwingtards reading this) ~ 'other' ~ probably don't think their religious beliefs are mere opinions, and they'll fight you on that point alone before you get to the meat of the argument.
Maybe I should use the phrase, Religious absolutist. Absolutely their way or the hiway....to hell.
-noun, pl. -ries.
1. stubborn and complete intolerance of any creed, belief or opinion that differs from one's own.
That doesn't necessarily make anyone on either side(s) a bad person. I prefer to judge these matters in the pragmatic political vein and shall strive do do so in the future.