Benny, Henry... Doesn't matter. Regardless of whether or not they believe the felgercarb they spew, it's still felgercarb. Have people walked in in pain and left feeling better? Yeah, but it wasn't "the power of God". You focus hard enough on something else, you won't feel anything. It's either for the same reason as why you don't feel pain when you're angry, why you don't notice it when you're on laughing gas,(Like, at the dentist... 'Course, I'm just going with what I've heard on this one, as I've never needed gas.) or how people end up doing crazy things under extreme stress.(Incredible feats of strength, for instance.)
The human body is capable of much more than what it normally does. Whether natural or artificial, you just need the right chemicals in your system to do them. These situations trigger the release of chemicals in the victim's(What'd you call 'em?) brain, and they think "Whoopee, I'm not..." I don't know, dead?
'Course, I don't take stock in biblical writings, so, ya know... "Though shalt not kill", not really a problem for me. It's really more the "If you kill, we'll throw you in a federal, pound-you-in-the-ass prison" that acts as a deterrent...
*Covets his neighbor's wife.*