Tem was the most abstract Egyptian god. In the myth cycle of the city of Heliopolis, Tem was the creator, the "God from Whom all Gods emanate",

The Egyptians believed there had been a time when nothing was in existence - no sky, no earth, no humanity; the gods had not yet been born, nor had death yet existed. A source of creation was necessary in this nothingness. To the Egyptians, creation was an act of generation; of birth.

Since the yearly Nile flood was an example of generation close by them, they pictured the ultimate source of all created existence as being the 'primeval waters' - the boundless "Waters of Potentiality". Out of those waters, the god Tem arose.

By one of two methods Tem was said to have created both all creation and all the other gods: either through self-impregnation as the "Great He-She"; or through his tears, mucus or other bodily fluids.

Tem first created Geb ("Earth"), Nut ("Sky"), and sometimes Ra ("Sun"). Geb and Nut then had five children who were the five gods of the
Heliopolitan Pesedjet ("Great Names"): Osiris, Horus, Set, Isis, and Nephthys.

As the driving force of the invisible breeze Tem was originally a God of wind and ruler of the air. In later times, He assumed the symbolism of the setting sun, receiving the Boat of Ra as it descended to the western horizon. Tem wore the pschent, or Double Crown, signifying his dominion over Upper and Lower Egypt.

In some versions Tem began creation alone in the Nun, the deep void, like the Biblical Yahweh. Tem was very similar in concept to another creator god in African religion: Olodumare of Ifa (worshipped by the Yoruba of Nigeria).