The Mysteries of Greek Mythology

In ancient Greek, the word "mystery" means the unutterable, secret part of ceremony or worship, which does not become observable to individuals that have not been initiated. Etymologically, the word is produced by the verb "myein", which means "to close eyes and lips". The individuals, who have been initiated in the mysteries, of transcendental, are not allowed to announce them to others, who are not initiated; they should keep their mouth closed.

The ancient Mysteries were perhaps the superior intellectual heritage in Ancient Greece. They were mainly concealed adorations, where one should be first initiated. The follower of this worship was the Initiator (in ancient Greek, Mystis) and the person, who initiated the followers, was the Initiating (in ancient Greek, Mystagogue). Each community of mysteries had common dinners, common dances and the rituals, where people, who joined in the same dance and participated in the same events, felt for ever united.

In their internal significance, mysteries presented the eternal truths, both natural and intellectual that had been preserved in the passage of thousands of years.

From the little information that we have about the ancient Greek mysteries it appears that they presented allegorical representations, which symbolized the destinies of souls after death, the law and the unity that interconnects all the beings. They were also ritual associated to the fertilization of the ground and the covetable rain.

The most important mysteries in ancient Greece were the Eleusinian mysteries.

Although, most of the ancient populations imagined their Gods to live in the sky, the deity of the ground is much older. Called in the ancient Greek "Gaia", with the passage of centuries, it acquired the name Demeter, which very probably means "Ground mother" (in ancient Greek "mitir" means "mother"). The adoration of Demeter had a clearly rural character and it was related to the circle of work from seeding to harvest. It was widely spread in the all Hellenism from Asia Minor to Italy . Having as a starting point the fertile plains of southern Thessaly , Eleusinian mysteries gradually acquired Pan-Hellenic scope.

Representing the possibilities of rural religion to the achievement of human happiness, the Eleusinian mysteries had explicit eschatological teaching. According to the Homeric anthem for Demeter that is explanatory of the general adoration of the goddess, apart from Demeter, who was the leading character of the mysteries, there was also her daughter, Persephone. Persephone represented the eminent spirit of vegetation, which disappeared from the surface of ground and was coming back after Persephone's determined eve in the Down World.

The fable of Demeter and Persephone constitutes the centre of adoration of the Eleusinian mysteries. It is considered that Eleusinian mysteries were founded by Evmolpos in the 1400 BC and that they began to operate function officially the 8th century BC.

Sources:

http://www.uwec.edu/philrel/faculty/beach/publications/eleusis.html
http://www.eleusinianmysteries.org/