User blog comment:LurkerLordB/Religion in a world without Christianity/@comment-1593341-20120424094112/@comment-32656-20120429214037

The split between it being based in Christianity, and the Pagan Arab religions, is around 50/50. without both, Islam in any form we could remotely recognize won't exist. And with that change, the factors that allowed it to gain so many followers- i.e. similarity to the pre-existing religions - vanish too.