Is someone who follows the Hanafi, Shafi‘i, Hanbali, Maliki, Ja‘fari, Zaydi, or Ibadi school of thought a Muslim?
[Followers of] all of the schools of thought of Islam are Muslims. The criterion for being Muslim is bearing witness to the oneness of Almighty God and bearing witness to the messengership of the Prophet (S). Whosoever says in Arabic, ‘I bear witness that there is no god but Allah and I bear witness that Muhammad is the Messenger of Allah’ is a Muslim and will be covered by all of the laws of Islam making his life, his honour and his property inviolable. This is the case whether the person is someone following the Ja‘fari school of thought, the Zaydi [school], or the Sunni [schools]; whatever the school of thought might be, whether it be Hanafi, Shafi‘i, Maliki, Hanbali, Ibadi, and so on1.
What are the limits on takfir in Islam? Can one pronounce takfir on a Muslim who follows one of the well-known schools of thought in Islam or hold Ash‘arite or Mu‘tazilite beliefs? Is it permissible to pronounce takfir upon those who follow genuine Sufi tariqahs?
The criterion for unbelief (kufr) is denying divine oneness and the messengership. Therefore, pronouncing takfir upon the followers of Ash‘arite doctrines, the Mu’tazilites, or followers of Sufi tariqahs is not permissible. This is because they acknowledge divine oneness and messengership. For this reason, from the time of the Imams (A) until the present, we cannot find from among the great ‘ulama anyone who had pronounced takfir upon the followers of the other schools of thought2.