Hi, New here, but saw the topic and not many Muslims chiming in so I felt the need to. ISIS is not a Muslim movement. If they are trying, they are attempting to be successful like Christianic Satanists (Satanists who accept Christianity is a path but choose to follow the opposite in hopes of being the right hand of the devil.)
Proof is as simple as Quran 5:32:
Because of that, We decreed upon the Children of Israel that whoever kills a soul unless for a soul or for corruption [done] in the land - it is as if he had slain mankind entirely. And whoever saves one - it is as if he had saved mankind entirely. And our messengers had certainly come to them with clear proofs. Then indeed many of them, [even] after that, throughout the land, were transgressors.
Also, religion cannot be made compulsory as they are trying to establish with the convert or die policy Quran 2:256:
There shall be no compulsion in [acceptance of] the religion. The right course has become clear from the wrong. So whoever disbelieves in Taghut and believes in Allah has grasped the most trustworthy handhold with no break in it. And Allah is Hearing and Knowing.
I can't seem to find it now, but In Sunnah (what makes Shia and Sunni different is accepting the Sunnah of the Prophet (PBUH) ) it states that when Mouhammed (PBUH) came upon a Jewish settlement during the Meccan War, the soldiers asked if they should go and destroy it. Mouhammed's answer was "No", leave those in prayer as they are not opressing you. (this is obviously my words describing what I have read, and not direct)
They have killed Sunni Muslims by the thousands, Christians who were peaceful and minority and certainly not oppressive by the hundreds, and Shia Muslims by the (at least) hundreds. This fact alone disqualifies them from Sunni Muslim classification, Muslim classification, and any other classification than Evil.
To further this view, their clerics have stated that once their fight in Syria and Iraq are done, their next target is the Kabaa.
Am I saying that all those in ISIS are horrible, no. But I am saying that the ones who are not are being misled. I've read and heard many accounts of people signing up to go there to fight Assad for his crimes that the International Community seems to have let slip by. If it weren't for the attacking innocent people, I could stand behind that cause. But, the fact is they have and continue to place a black mark on Islam by doing that which is forbidden in the name of Allah.
Furthermore, there has been a lot of political discussion on who they started out and where they got their weapons. They started as a group loosly tied to Al-Nusra, Al-Queda, and other terrorist organizations as a third perspective in the battle between Assad Loyalists and the oppressed citizenry (Kurds were staying out of it at that point but they refused to fight alongside the group now known as ISIS which has led to the conflict in unnofficial Kurdistan). They got their weapons (Humvees, tanks, and some of their light arms) from what was left after the last Iraq war by the US. Others they have purchased over the years through the ties to the Terrorist organizations that founded it. At 1 time the US was considering backing the group as it seemed to be tied to the oppressed citizens under Assad. Although some conspiracy theorists seem to think we were involved, but as far as public knowlege (ie. Al-Jazeera, BBC, various US based news companies) it never panned out.
Then there are the other conspiracy theorists that say the Israeli government is funding them, with reference to the fact that ISIS seems to have not made any attempt to help Palestine or mentioned targetting Jerusalem to retake it for the Muslims (a common goal for most Jihadi wannabe Muslims).
Long post, lot to say. Salaam Allahikum everyone.
