Short form of fanatic is FAN! Baseball fan, football fan, metallica fan, britney spears fan, bush fan, you name it! We're all fanatics people, well
most of us!
Fanatic: Someone marked by excessive enthusiasm for and intense devotion to a cause or idea
The thing is, the fanatic doesn't have to "believe" anything, he just has to be deeply attached to.. well anything. For example, if someone is a
tattoo fanatic, he might have 155 tattoos on his body, but doesn't mean he "believes" anything about the tattoos, he's simply obsessed.
However, a believer and a fanatic can be the same thing, as for example "Fanatical Christians" or "Fanatical Muslims", where you take your BELIEF,
then you obsess over it, where everyone not of the same belief is an "idiot, infidel, etc". That's fanaticism, and in fact, "FAN" is accurate in
describing it. What happens to a "YANKEES FAN" when he sits in ths middle of "RED SOX FANS" crowd and says "GO YANKEES!". He doesn't go home
Fanatic is someone obsessed.
Believer is someone who assumes something is true, when he has absolutely no idia, usually because he WANTS to assume it, because it sounds GOOD to
him, and possibly because he's AFRAID to think otherwise under the threat of punishment, and is TEMPTED to believe in whatever it is, due to some
sort of "promised reward". You can say belief is obsession, but I'd call it more of a "stagnation" where you stagnate your progress, and progress
is defined by how much you LEARN (aka how much actual KNOWLEGE you obtain). The more you believe, the less you know, and this means you do not WISH to
KNOW, because knowledge doesn't interest you.. your belief (aka assumption) does
That's just my 2 cents