Actually there's more to it than that. It really comes down to : Do you believe heaven is a celestial whore house, where Allah's houri/daughters spread their legs to faithful jihadi murderers who killed their way into heaven? If you do, you're a muslim. If you don't, you're a sane infidel.
http://www.chiesa.espressonline.it/dettaglio.jsp?id=7025&eng=y
Read the whole thing, but pay special attention to about halfway down the page. There's a little something about the supposed "virgins" which if true, is going to piss off a lot of Mohammedans.