What gives a religion the right to claim their fantasy is correct and the rest false?

[vorlon13]

Science is based on evidence, facts, and theories supported by evidence and fact.

So what exactly gives one religion the leg to stand on and say "this religion is true, the rest are false", when there is no evidence or fact to back up their claim?

 By and large, I don't we see too much of that 'out in the open' these days.  I think some denoms keep such criticisms in house, such as the one one of my sisses attends.  They get an occasional anti JW or anto Mormon sermon, but I don't think their float in the county fair parade would ever highlight such a viewpoint.

Recently the Omaha World Herald reported an outlying rural school district had some kind of assembly for their students about drunk driving (it's bad, m'kay) and afterwards apparently some of the folks who put on the program passed out some anti-Mormon tracts.  It garnered considerable negative attention.

And as for deeming a specific schism in the Christer orbit a 'false religion', it's pretty damn easy to do.

If they aren't handling timber rattlers or swilling polonium tea, or do allow menstruating females in the building on Sunday, I can guaranty, they ain't doin' it right.

I suppose it's even more fun with a schism like the Mormons to prove their falsity; they have quite a propensity of ignoring and/or changing virtually all their key (and minor) doctrines and then having had a brain fart along the way in regards to publishing for general distribution the incriminating paper trail they themselves generated on their faithlessness and perfidy.

For most other faiths, even if they do claim Biblical Literalism and Inerrancy, the ingrained habit of scripture cherry picking and Bible buffet does make pointing out the missed verse or dogmatic contradiction perhaps a little less stinging as a rebuke.