I'm not sure if most Christians even believe in God anymore. Church's are places to go to have a social life with other "nice" people, they may not worship or study much at all.
As a consequence of this I don't think most church goers believe in Hell either. But the version brought forth by Dante still persists in popular belief this then brings about the typical binary thought pattern of Europeans where one either must exist and the other must not. Given this simple choice, most reject the idea of Hell because they can't believe that a loving God would consign someone to that fate.
So no, most who call themselves Christians don't believe in the inferno of Dante. But what hell is really, is being alone for eternity.
As Smoholla The Dreamer said, "People ask if there is life after death, but what it is, is death then life."