Twelvers believe that their twelfth Imam, Muhammad al-Mahdi, has been concealed by God, though he remains responsible for the affairs of men and their inward spiritual guidance in his state of occultation (874 CE-present). While various sects disagree about the identity of the eschatological Mahdi, the belief in him remains popular among all Muslims, possibly owing to numerous traditions to this effect in canonical Sunni and Shia sources.
