Muhammad did not create Islam.
In Dante’s « The Divine Comedy », the hero, traversing the 9th circle of hell, sees Muhammad.
There, he is not presented as a false messiah, but as an Arian Christian bishop who divided Christianity.
For a long time Islam was seen as but a schism of the Judeo-Christian world, a duality of a Judaic schism or Christian schism.
Only later did it assume the form of a fully fledged religion, with the constitution of sunnah and sharia (with the help of haddiths) by the « ulemas » for Sunni Muslims and ayatollahs for shia. Historical clues may perhaps tell us the time of the mutation of Mohamadism into Islam as we know it. The grammar of Esperanto, the so-called Arabic language needed to make the sacred texts of Islam, was the work of a North African who lived in the 12th century. The terms « Islam » and « Muslim » did not appear in the European literature, that of France and Britain, until the 16th century for the « muslim » and 17th for « Islam ». Notably, these countries fought against the » muslims » and « islam » in the Crusades, from 1095 to 1492.
In both the case of Sunni and Shia sects, a clergy caste of priests needed a (new) oracle who could achieve indisputable control, no matter what he should say.
In Kabylie this caste of priests are the marabouts. Another time, the priest / shaman served as intercessor with deities, spirits and all supernatural entities. They wrote and uttered unintelligible words to uninitiated humans.
With Islam our marabouts, wrote in Punic liturgical language (wrongly described as Arabic writing) and recited surah in Esperanto said Arabic language, if someone is sick they will write a surah on a piece of cloth and put it on the wound or on the forehead.
Obviously to keep their grip on the Kabyle it was necessary at all costs that they remain illiterate.The writing is therefore reserved for the initiates.
The ayatollahs are probably one of the oldest clergy in the world, Zoroastrian clergy, or muslim clergy whatever.