The divine power of the Gods is not without limits, for every action there must be an equal and opposite reaction. As the Gods of the Universe spend their powers in order to give their wishes and desires form, they require the worship of the masses to recover their spent energies. This is done by allowing the worshippers to collect mana from the natural endless flow of magic through the multiverse (referred to by thaumatology scholars as “The Weave”) into their bodies through the mere action of breathing.
The more powerful mortals of Oerth have been known to harness greater amounts of this energy to go beyond standard mortal limits, using small rituals, magical chants and enhanced physical prowess. Guidance has been passed down by various cults, monastic orders and holy orders.
When performing rituals dedicated to their chosen Gods, this power is purified, before being released from their bodies and then absorbed by the God to restore their divine powers. Without a cult of worshippers, a divine entity would be unable to recover their connection with the weave and would fall behind in the complex game of chess played by the Gods.