Eleusinian mysteries

The Eleusinian mysteries were annual celebrations for the cult of Demeter and Persephone in ancient Greece of strictly secret initiations into secret knowledge and experience, centered at Eleusis, observed from 1600 B.C. until A.D. 392. Britannica Encyclopedia calls them the "most famous of the secret religious rites of ancient Greece." The nature of these esoteric initiations and knowledge remain unknown. Murder and sexual impurity disqualified applicants who petitioned to participate. The testimonies of initiates only offers evidence that lives were said to have been permanently changed for the better, and that initiates no longer feared death and the afterlife. There are some slight indications in the ancient sources that the least indirect betrayal of the seal of secrecy was punished by a violent and painful death at the hands of dedicated assassins.