Accounts of Roman Emperor Julian (c.331–363 CE), also known as Julian the Philosopher, and the last non-Christian ruler of the Roman Empire suggests that he was an initiate and follower of the God of the Seven Rays (cf. his Hymn to the Solemn Sun and Hymn to the Magna Mater).
This reference to a God of the Seven Rays is found in the Chaldean Oracles of Zoroaster and has Mithraic overtones. We do know that in Zoroastrianism, God, Ahura Mazda is associated with the divine heptad of the Amesha Spentas, divine attributes personified as arch-angels, and that the body of God is described (as best as the incomprehensible can be understood by human beings) as a divine light. It is also of interest to note that in early Christian iconography, the dove of the Holy Ghost as well as the image of the Madonna are often shown with an emanation of seven rays. Even in the present day Byzantine-style Cathedral in St. Louis, Missouri, the center of the sanctuary has an engraved circle with symbols of the Holy Trinity - and the inscription of which reads: "Radiating from this symbol are seven rays of light representing the seven gifts of the Holy Ghost." Similarly, Hinduism too has several references to seven rays associated with the Sun as a giver of life, with the deity Vishu and deity of fire, Agni, philosophically interpreted by Sir Aurobindo as "the seven forms of the Thought-principle."
Julian rejected Christianity in favour of neo-Platonism causing him to be called Julian the Apostate by the Christian Church. The Neoplatonists used the Chaldean Oracles of Zoroaster as their scripture. His mission was to bring the Roman Empire back to its ancient Roman values in order to save it from "dissolution". As we have noted above, there are indications that his beliefs were also influenced by Mithraism which was prevalent throughout Europe at that time.
As see Julian the Apostate, Julian the Emperor's Oration upon the Mother of the Gods (1888).