It would appear that the religion of Islam covers a wide spectrum of beliefs with different interpretations. Some of the sects within it are very peacefully while others, like ISIL, are not. It also appears that the various sects each feel that the others have misinterpreted the true meaning of the faith. This really an issue for Muslims to resolve however,  if it is to fit into the 21st century the religion of Islam is badly in need of a major overhaul. 
In the interim perhaps we could make a dent in this kind of thing if we dealt with the mosques and educational institutions which preach a very conservative version of Islam, (salafism/Wahhabism/Muslim Brotherhood organizations for example) as these are the groups that are preaching a more conservative, one prone to a more violent interpretation