OK i have two questions..help me out with these.?

OK the biggest part of the Christian community agree that the work sheol means the rave and not the hell depicted by Dante Aligheiri but in his "vision" Hell was a place of fire and chains and torment. Now in the Koran there is a very similar version of hell. So if there was a mistranslation and sheol means grave and dante was wrong why is it that the Quran which was written round 610 when dante lived more round 1200 AD. So if there is in fact no hell how is a description of hell so similar between the two assuming Dante did not read the Quran. Now question 2. The Christian hell is reserved for all unsaved (jews, athiests, muslims etc.) whereas the muslim hell is reserved for any nonmuslim and the jewish is reserved for anyone who does not believe there is one true GOD and abide by its commandments and noahide laws for gentiles. So basically you have a 1 in 3 chance of going to some kind of hell. It has been said that the Quran cannot be disputed and is infallible ( haven't had alot of time to research this). And if athiests are right you go nowhere (sounds nice). So who is right? How is the Quran said to be infallible? Please explain ty.