Back when I was in undergraduate school I became interested in ancient Greek vase painting as well as the Eleusinian Mysteries. To the left is a drawing I did in the late 1970s showing the demi-god Triptolemos in his winged chariot. He was an important mythical figure portrayed in the famous Eleusinian Mysteries of Attica, Greece. I believe he, a pivital character in the depiction of the sacred mysteries, was the archetypal image of the full initiate into the Mysteries. Being the first initiate, the eponymous torchbearer, so-to-speak, of all the thousands upon thousands of men and women initiated at Eleusis in antiquity, he attained knowledge of the afterlife which gave him demi-god status and he becomes a beloved servant of the goddess Demeter. I think it is this same status that initiates believed they also attained by their participation in the mysteries. To them were revealed the secrets of the afterlife and to them was given the assurance that they would have a vital life after death.
As a servant of Demeter, the goddess of wheat, it was believed that Triptolemos traveled throughout the world on his winged chariot teaching humanity the secrets of agriculture and the hope that like wheat that is buried in the earth but then burst forth in life, they too can share in life-after-death (represented in the myth of the return of Persephone, the daughter of Demeter, from Hades [Death]).