When the average Islamic State (IS) member is asked why he is fighting, he typically responds, “So that Sharia prevails and Islam’s banner stays high.”

Marwan Shehade, an Islamic scholar and expert on jihadist groups, told Al-Monitor, “There’s no doubt the organization is built on three main elements: the Sharia, the military might and media. Their main slogan is derived from Ibn Taymiyyah’s famous saying, ‘The foundation of this religion is a book that guides and a sword that supports.’ By ‘a book’ they mean the Quran and religion.”

Despite the debate over whether IS represents Islam and what “true Islam” is, Islamic movements, sects and scholars perceive IS as truly believing it is enforcing the rule of Allah according to the Quran and the Hadith under the guidance of the organization’s Sharia Council, probably the group’s most vital body. The council’s responsibilities include overseeing the speeches of the self-declared Caliph Ibrahim (Abu Bakr al-Baghdadi) and those under him, dictating punishments, preaching, mediating, monitoring the group’s media, ideologically training new recruits and advising the caliph on how to deal with hostages when it is decided to execute them.

It was the Sharia Council that advised on the burning death of Muath al-Kasasbeh and the slaughter and shooting of dozens of Syrian and Iraqi soldiers as well as James Foley and other hostages. A former IS mufti who spoke to Al-Monitor in Iraq in January said, “Such decisions are made after thorough readings into the practices of the prophet and the first generation of Muslims.” At the time, IS had not yet burned a person alive. Muftis across the Middle East denounced the burning death of Kasasbeh on the ground that such a form of killing is an abomination under Islam, no matter the alleged justification.