pronounced "maw-dee"
(Persian and Arabic have two "a" sounds: an "aa" sound as in "father" and another "a" sound as in "cat". Usually, in transliteration, if it's the longer "a" sound, two a's will be used, and one for the shorter.) This is not one of those cases. It might more accurately be spelled "Maadi" depending on the transliteration.)
(from
http://i-cias.com/e.o/messiah.htm#islam) "The ideology of the Mahdi in Islam has many similarities with the Jewish/Christian Messiah. The ideology is central in Shi'i Islam but has a certain presence in Sunni Islam as well.
While Christian and Jewish thinkers would say that this ideology is strongly influenced by their two religions, Muslim thinkers would say that Mahdi represent the true form of saviour figure, and that Messiah in Judaism and Christ in Christianity represent deviations from the original doctrines.
Mahdi is a character that belongs to the last period of mankind, and his purpose is to restore the faith, and bring Islam back to its pure origins and provide for the belivers a society where they can perform their religious duties in a correct manner.
The Mahdi is not mentioned in the Koran, but belongs to theological developments starting from the 9th/10th century BCE.
The Arabic term "mahdi" is best translated with "divinely guided one". It is a Saviour figure in Islam, for which there are several different interpretations in Sunni Islam, and one dominant interpretation in Shi'i Islam.
The "mahdi" of Sunni Islam is just one of several important figures, while the "mahdi" of Shi'i Islam has a real eschatological importance, and is in the future the most important figure for Islam as well as the world.
The main principle of the mahdi is that he is a figure that is absolutely guided by God. This guidance is stronger form of guidance than normal guidance, which usually involves than a human being willfully acts according to the guidance of God. The mahdi on the other hand, has nothing of this human element, and acts the will of God directly.
The figure of mahdi, nor his mission, is not mentioned in the Koran, and there are practically nothing to be found among the reliable hadiths on him either. The idea of the mahdi appears to be a development in the first 2-3 centuries of Islam. In the case of the Shi'i mahdi many scholars have suggested that there is a clear inspiration coming from Christianity and its ideas of a judgement day in the hands of a religious renewer.
While there are many similarities between the Mahdi and Messias, there are also many variations over the Mahdi theme, which have differed from time to time and from region to region.
The first time we hear of the term "mahdi" is in 686 CE, by the Muslim leader Mukhtar Thaqafi, for Muhammad bni l-Hanafiya (see below).
SUNNI ISLAM
There are more than one way of defining the mahdi in Sunni Islam, but never is it given such an importance as we can see it in Shi'i Islam:
1. "Mahdi" has been used as an honorific title for several prominent figures in Islam. This applies to Ali, the 4th caliph; his son Hassan; as well as the ummawiyy caliph Umar 2. In the latter case, theologians meant that Umar 2 was the 1st of altogether 8 renewers of Islam. The last of these 8 would be a figure simply called Mahdi or Isa (Jesus).
2. When "mahdi" was used for the abbasid caliph Nasir, he was defined as the final mahdi, and there were no need to expect any future mahdis.
3. "Mahdi" has sometimes been used for converts to Islam, because these people are believed to have been guided by God to find the truth.
4. "Mahdi" has been frequently used for military leaders, both leaders suppressed Muslim were calling for, as well as leaders that appeared in flesh and blood. Among the most known are El Mahdi of 19th century Sudan, and Ibn Tumart of 12th century Morocco.
SHI'I ISLAM
Even in Shi'i Islam, there are variations, but these all give the Mahdi an elevated and unique position. These are the known variations:
1. In the now extinct sect of Kaisaniya, founded around Muhammad bni l-Hanafiya, son of Ali with another wife than Fatima, this Muhammad was defined as "mahdi". Muhammad appears to have refused this status, but nevertheless the Kaisaniya sect developed especially after his death. They developed a theology where they waited for his return from his grave in Mount Radwa, where they believed that he was living, and not dead."