But Arabia was also home to monotheisms, like Christianity and Judaism and even a bit of Zoroastrianism. So the message that there was only one god wouldn't have been, like, as surprising to Muhammad as it was, for instance, to Abraham. Also, and this will become very important, the northern part of Arabia was sandwiched between the Byzantine Empire and the Persian Sasanian Empire, and you'll remember, those guys were always fighting. They were like snowboarders and skiers, or like the Westboro Baptist Church and everyone else. At its core, Islam is what we call a radical reforming religion. Just as Jesus and Moses sought to restore Abrahamic monotheism after what they perceived as straying, so too did Muhammad. Muslims believe that God sent Muhammad as the final prophet to bring people back to the one true religion, which involves the worship of and submission to a single and all-powerful god.