Well that's what faith is, belief in something without evidence/against evidence.<quoted text>
No, it's not. It's bad. How can faith be good? It's a guess.
Faith can be in anything, however absurd. Of course you can have faith in jumping off of cliffs. I'm sure that people jumped into volcanoes on faith. If there were a religion recommending either, the faithful would be praised, and would jump.
Someone can have faith that gravity doesn't exist, but that doesn't make it even close to true.