In Rome’s museums I was fascinated by the way in which Romans incorporated into their culture beliefs from Egypt, the Middle East and Persia. Christianity was the one we think of today, but another important one was the cult of Mithras. Wikipedia has a very long article about him. He was originally a Persian or Indian god, associated with Zarathustra and probably with the Mitra of the Rig Veda. He was believed to have sprung from a rock and was usually worshiped in underground temples. The content of their rituals or beliefs is not very well known. However, during the fourth century the cult of Mithraism became prominent and spread across the Roman empire and signs of the cult have been found everywhere from North Africa to Northern Europe. Perhaps, if the adherents of Mithra had not been so cruelly persecuted by the Christians, we would still be under the sway of Mithraism today.