Islam is not the specific focus of our study. We are interested in it because it is a major amplification to the ongoing animosity between the progeny of Isaac and the sons of Abraham. Muhammad died in the arms of Aisha at the age of sixty-two on June 8, 632 AD. There is much discussion and conflicting views regarding the cause of his death. Some say he was poisoned. He had not appointed a successor. Muhammad had at various times eleven current wives and at least two concubines, but no son survived. Ali, being the nearest blood relative as Muhammad's cousin and son-in-law since he had married one of his daughters, was the closest to being a male heir. However, Arab communities recognized two forms of leadership, one of hereditary, and the other through selecting the best qualified person. In this instance the Muslim community selected a successor, Khalifa (pronounced Caliph), by the second method. Abu Bakr was chosen, but some preferred Muhammad's next of kin, Ali, and from this uncertainty the embittered division of Islam between Sunni and Shi'a Muslims came into being a generation after Muhammad's death. Robert Morey makes the following comment regarding Muhammad.
The amazing genius and forceful personality of Muhammad enabled him to take a minor pagan cult of the worship of the moon god Allah and to turn it into the second-largest religion in the world!