Mithraism was a mystery religion with devotees sworn to secrecy. Nothing could be spoken or written down. What little is known of Mithra, the god of justice and social contract, has been deduced from reliefs and icons found in temples. Most of these portray Mithra clad in a Persian-style cap and tunic sacrificing a white bull in front of Sol, the sun god. From the bull’s blood and semen, grain, grapes and living creatures sprout forth. Sol’s wife Soma, the moon, begins her cycle and time is born. The letters ‘VSLM’ that are inscribed on many Mithraic stones are part of a secret code thanking Mithra for his good deeds and are recognizable only to the faithful. Mithraism and Christianity competed strongly because of the striking similarity in many of their rituals. Both involve shepherds, an ark built to escape a flood and a form of baptism. Devotees knelt when they worshipped and a common meal – a communion- was a regular feature of the liturgy.
The Mysteries of Mithra, which came to flower in the near east during the Hellenistic age as a kind of Zoroastrian heresy, and in the Roman period was the most formidable rival of Christianity… Celebrants wore masks representing animals of the Zodiac: for astronomy was undergoing a new development in this period through an application of Greek thought to the data of the centuries of Sumero-Chaldean observation. In all religions of the age, the Zodiac had come to represent the bounding, ever revolving sphere of time – space – causality, within which the unbounded Spirit operates unmoved yet moving in all. – Joseph Campbell