Devil Worship: The Sacred Books and Traditions of the Yezidis is a study about ethnoreligious group of Yezidis who are considered a devil worshiping sect. Yezidis are a Kurmanji-speaking endogamous minority group who are indigenous to Kurdistan, a geographical region in Western Asia. There is a disagreement among scholars and in Yazidi circles on whether the Yazidi people are a distinct ethnoreligious group or a religious sub-group of the Kurds, an Iranic ethnic group. Yazidism is the ethnic religion of the Yazidi people and is monotheistic in nature, having roots in a pre-Zoroastrian Iranic faith. Since the spread of Islam began with the early Muslim conquests of the 7th–8th centuries, Yazidis have faced persecution by Arabs and later by Turks, as their religious practices have commonly been charged with heresy by Muslim clerics. Yezidis are considered to be devil worshippers by other ethnicities in the region. The book covers essential areas that give a vivid and complete description of this group and author goes to great lengths to investigate theories about whether the Yazidi religion was a sect of either Islam or Christianity.