” 21.  That Islam was invented by Muhammad, is proven by the fact that the Koran indicates that the Christian trinity is made up of the Father, Son and Mary (Jesus Mother). This heretical doctrine was indeed taught by the Collyridlans and Ebonites who had fled to Arabia. Muhammad learned Christian doctrine through these heretics and incorrectly assumed it was representative of Christianity in general.”

Quoted from:  http://www.bible.ca/islam/islam-encyclopedia-westerners-need-to-know-list.htm