The word Mahdi signifies “the one who is guided,” meaning the “well guided.” Many prophets and just men can be called “well guided.” The Mahdi, from the fact that he is situated at the end-times merits another epithet: “the awaited.”
One hadith transmitted by Ibn Maya affirms that the Prophet has said: “There is no Mahdi, then, but ‘Issa ibn Maryam (Jesus son of Mary).” In effect, for Muslims, ‘Issa (Jesus) is not dead, he has been elevated near God (Sura “The women” 4, 157-158) and will return at the end of time, but the knowledge of the Hour is a divine prerogative (Sura “The Wall of A’raf” 7, 187).
Yet this hadith is refuted by others, and for Muslim belief the Mahdi is not ‘Issa (Jesus). In the 14th century, the celebrated Syrian jurist Ibn Taymiyya transmits that the Prophet said: “His name shall be the same as mine, and that of his father the same as mine, that is to say, Muḥammad ibn ‘Abd Allah, and not ‘Isa ibn Maryam [‘Issa (Jesus) son of Maryam].”
Certain Muslims do not believe in the coming of the Mahdi because it is mentioned neither in the Koran nor in the original part of the collections of Hadiths by Al-Bukhari and by Muslim.
Other Muslim historians, without denying the coming of the Mahdi, are very skeptical about most of the texts that refer to it: the celebrated historian Ibn Khaldun writes: “Know that since always Muslims are convinced that at the end of times must come a man issued from the family of the prophet to reestablish the religion, restore justice, guide the Muslims, and govern the Islamized nations; his name will be al-Mahdi. The appearance of the Antichrist (ad-Dajjal) and all the events relative to his coming will unfurl; then ‘Isa will redescend and kill the Antichrist, and the Mahdi will help to exterminate him. It is said also that the Mahdi will conduct the prayers of ‘Isa. […] Regarding all the writings reported by the imams as describing the particularities of the Mahdi and predicting his coming at the end of time, very little would resist a critical examination, it would even be very rare.” (Al-Muqaddima, pp. 330-331 and 342).
In the course of the centuries, certain persons were considered as the Mahdi, as for example, the Sufi As -Sanusi (1844-1902), who fought in Libya against the French and the Italians. His admirers pretend that he is not dead but still lives in hiding and that he is the awaited Mahdi. Another example, Ibn Surayi in the year 734 opposed the governor of Khorasan, saying: “Mine are the black banners.” He had an associate al-Karmani, but they ended by turning one against the other. The troops of the false Mahdi were defeated. He was killed in 746. And again, Ibn Tumart, of Berber origin, born around 1078, forged a genealogy to suit him, launched a jihad against the Almoravids, and died in 1130. “No Muslim historian has ever adventured to try to number the imposters and the illuminates who attempted to pass themselves off as the Mahdi of Islam, but all are in accord in saying that their number was considerable.” [1].
Since Islam does not believe in the divinity of Christ and confounds his glorious coming with a material, regional event, it is structurally vulnerable to the seduction of a false Mahdi (if it is possible there can be a true Mahdi!). Assuredly, never would a Christian confound a Mahdi, who has a terrestrial, material body and conducts a regional battle, with the Christ who will return in glory, with a glorious body, comparable to that of the resurrected Christ, and manifested to the entire world.