Final answer:
The main form of religion in Mecca before Muhammad and his followers took control of the city was polytheism.
Step-by-step explanation:
The main form of religion in Mecca before Muhammad and his followers took control of the city was polytheism. Arabian polytheists worshipped idols and totems as physical representations of divine spirits. The Kaaba sanctuary in Mecca, which contained a variety of religious idols, was a site of religious pilgrimage during this period.