Rev. Martin Luther King wrote a paper on Mithraism in 1949. He also received an A grade on the essay on his presentation skills on an otherwise difficult concept.
The details of MLK's papers are in Stanford's website - http://mlk-kpp01.stanford.edu/index.php/kingpapers/article/volume_i_13_september_to_23_november_1949/.
I witnessed Mithraism (worship of Mitra) when I was in Rome, Italy. Mithra (AKA Mitra) is Vedic and Zoroaster's view of the powerful phenomenon that guided Sun to spring.
Yes, from winter to spring - a resurrection, a rebirth of the Sun - the procreator, the God of the yesteryears.
The Vatican Museums and Basilica of San Clemente offered me direct insights into Mithra worship - a likely predecessor to Christianity - a long forgotten history of reconciliation of a prevailing system to the great spiritual movement that was gaining sturdy influence with its purer conception of God.
You can witness the mercy, the power of the Sol-God only in darkness of the labyrinths in the dungeons at San Clemente.
Mithra is the phenomenon that symbolizes the movement of the Sun away from a Taurus culmination of summer solstice. The slaying of the bull - "taurobolium", is so evident in the sculptures in the dungeons in Saint Clemente's basilica. The presence of Ashvins in the rock sculpture; could also be Gemini twins; Saturn giving out the weapon to destroy the bull; Sol and Luna blessing the act; Sirius the dog, the Lunar nodes shown as a serpent and Scorpion (scorpio) all active participants marked the new epoch - the birth of a new era.