Pronouncement that someone is an unbeliever (kafir) and no longer Muslim. Takfir is used in the modern era for sanctioning violence against leaders of Islamic states who are deemed insufficiently religious. It has become a central ideology of militant groups such as those in Egypt, which reflect the ideas of Sayyid Qutb , Mawdudi , Ibn Taymiyyah , and Ibn Kathir . Mainstream Muslims and Islamist groups reject the concept as a doctrinal deviation. Leaders such as Hasan al-Hudaybi (d. 1977 ) and Yusuf al-Qaradawi reject takfir as un-Islamic and marked by bigotry and zealotry.