There were many Mystery Schools in Greece but only a few among the most important ones will be reviewed here:
a- The most important Ancient Greek Mystery School was that of Eleusis dedicated to Demeter and Kore. At first it was an agricultural cult of which Demeter was the “Grain Mother” or “Earth Mother” (mature grain), and Kore the “Maiden” (newly planted grain). As Kore sojourned in the realm of Hades she was also described as the queen of the Underworld. Later on, as Athens took over, the content of the cult and the rite changed and they became more mystical. The candidates to initiation had first to fast, then to bathe in the sea (body purification), to kill a young pig in honour of Demeter and Kore, and to participate in a procession from Athens to Eleusis carrying sacred symbols and performing unknown mysterious rites. Water was also poured into the ground as a symbolic representation of the impregnation of Mother Nature.
b- The Andanian Mystery School was very old and more or less as sacred as the Eleusinian one. Very little is known about these mysteries except that a sacred cypress grove and a spring were important factors in the ritual, and that many gods were worshipped.
c- The Greek God Dyonisos (known also as Bacchos or Bacchus) was the object of worship in many places. He was sometimes represented as a bull but also in more effeminate shapes. His followers lived in the forests. He was supposed to be present in raw meat, in wine, in various sexual objects, but also in the human soul. Initiation ceremonies included eating and drinking, sometimes tearing life animals to pieces and eating their raw flesh in order to capture Dyonisos’ power. In some cases sexual practices were also parts of the initiation.
d- The Anatolian Mysteries of the Great Mother Cybele and her lover, Attis, were very popular in Phrygia and in Lydia. Cybele was described as a mother goddess of fertility. Cybele and Attis were also worshipped in Rome, especially in the 2d century AD when even the main Roman festival was held in their honour. During the festival the participants first fasted, did not drink wine, and abstained from sexual activities. The participants carried a freshly cut pine tree into the sanctuary with an image of Attis; they then mourned in front of the tree to commemorate the death of Attis (from self-castration under a pine tree). Following this they flogged themselves until they bled and then spread their blood on Attis’ image (some castrated themselves too). The festival ended with a feast.
There were two types of followers of these mysteries:
i- The majority of the participants in these festivals saw them as theatre plays in which all had a role to play but they did not know the profound meaning behind them.
ii- The second category of participants had first been initiated in the mysteries hidden behind the play. We do not know the rituals of each of these schools of Mystery but they implied a long period of preparation of the candidates. On the day of initiation, they had to purify themselves, to fast, and to go through an elaborate ceremony in which the “secrets” of the school were revealed in a symbolic way. The new initiates were requested to swear not to reveal the secrets of the cult to any outsider.