Of course ISIS is perverting Islam. That's surely one of it's primary intentions. Already we see millions of US citizens backing a man (Trump) who has done exactly what ISIS set out to do - start a hate campaign against ALL Muslims. There is nothing in the Qur'an (as far as I'm aware) that says the things this radical group are doing are morally 'right' or will bring them 'glory with Allah.' No, they're misusing and misrepresenting religion in order to make us turn on each other. And they're succeeding.
ISIS claims to be Islamic, but by their actions and statements, they are perverting the real beliefs of the Islamic faith. Their violence towards people and their wanton destruction of their surrounding files in the face of the teachings of the Koran. Islam is fundamentally a non-violent religion that values human life. This is the opposite of the actions of ISIS. Further, the destruction of many historic sites and artifacts by ISIS is the antithesis of the historical teachings provided in the Koran.
I have no doubt whatsoever that ISIS is preying on the weakness of a few individuals to further an extreme interpretation of a religious text. This in turn makes it difficult to accept that others may hold a viewpoint not shared by them. To them (ISIS), anyone who refuses to fall in line is an enemy and has to be destroyed. Compassion and love for your fellow is not a notion this group has little to no willingness to embrace. What this all does, is lead to a hard line view of the world and a selective interpretation of religion, which makes it unpalatable in the eyes of it's supposed enemies.
I fully support that ISIS is perverting Islam because it's further effecting the people's opinions on Islam and their people. Not every Islamic person is a terrorist just as not every white person is of the middle class. ISIS is adding to the stereotypes and making life even harder for Islamic people who live in America.
If a Christian cult arose that followed every preaching in the Bible they'd be branded terrorists for killing people working on Sunday, allowing slavery and oppressing women. ISIS is the purest form of Islam- following the Quran to the letter. Reasonable religious people cherrypick the good parts and ignore the bad. Which is a good thing.
If a Christian cult arose following the exact teachings of the Bible they would be a terrorist group. Killing the unfaithful, those who work on Sunday, allowing slavery and oppressing women. ISIS is putting the exact teachings of the Quran into practice. Reasonable religious people of all faiths cherrypick the good parts and leave out the bad. That's how society works.