No religion is a religion of terrorism. ISIS and its affiliates are kharijites. they adore their leader, abu al baghdadi, as a divine "imam" or even "second to the prophet".
everything they act upon is all transgressed. like, destroying artifacts, judging and leading on every women and man, no merciful talk, and ignorance.
The prophet (saw) prophesied these people and that we are all to fight them.
ISIS will kill a non muslim simply for being a infidel which goes directly against the quranic teachings.