I thinks it's real but not legitimate.
By not legitimate it doesn't fairly represent Christians, it's not typical of their attitudes towards gaming, and I've read that among Christians, even among their own denomination those guys are regarded as wacky, far too radical and a bit of a joke.
There's far too many links to other sites in their network for it to be a parody site, I can't believe that people would go to all the trouble of setting up and maintaining multiple website, recording and publishing songs and videos, making clothing and merchandise, organising camps and meetings, just for the sake of parodying Christianity.
Also if it was fake, then surely by now some of the real sites it links to would have demanded it be shut down, or at least have those links broken.
It is funny as fuck however, and should be treated as the joke that it is, because you shouldn't give some the agenda's they're pushing any serious thought at all.
Just laugh at how clueless they are and don't think bad of all Christians (or other people with religious beliefs) because of it.