What makes this possible is that you have at least three groups of Muslims.
1) ISIS and other so-called extreme groups like Wahhabis are the real Muslims, if one cares to take the time to learn about the Koran. The Koran ORDERS a Muslim to do all the things Muhammad did in his time. You must read the ahadith (literature sources describing the words, actions, and habits of Muhammad) to understand what was permitted. Also, because of the way Islam was created and grew, Allah is really subsumed under Mohammad the Prophet. You cannot go to heaven if you only believe in Allah. You HAVE to believe in Muhammad as a minimum requirement. Therefore, Muslims will look to Muhammad and the ahadith about him to get advice on what they consider “appropriate” actions. The following two groups of Muslims merely open the door for the real Muslims to come in and take over once these two groups have laid the groundwork for a cultural takeover.
2) One group cherry-picks their way through the Koran and willfully ignore the parts that upset them or they cannot believe in.
3) The other group simply don’t know the Koran by print, only what has been told to them. The reason being is that 80% of Muslims cannot read classical Arabic using the early hijazi script, which the Koran is written in. How does one know to trust the person who is supposed to give them accurate information when they can’t read the script/language?
Remember all these points next time you see a Muslim spokesperson decrying the violence by such people and ask yourself whether the person is really being honest with you…