The main purpose of Greek religion was to enlist the aid and placate the anger of the gods. Although they did not have any set rituals to perform daily, their beliefs gave them occasions to religious acts daily. For instance, if a coin was found, thanks was given to Hermes, God of Treasure.
Their creation story goes something like this: In the very beginning was only the dark void and Gaea, the Earth. The Dark void alone produced Erebus and Night; Gaea gave birth to Uranus (the sky). Then together Gaea and Uranus produced the Titans (six male and six female giants), three headed monsters called the Centimanes and the Cyclopes.
The Titans were considered the ancestors of humankind, inventors of the arts and magick.