Ancient Roman carvings of Mithra – dated between 300-400 CE. Note similarity of this and ancient Vedic/Hindu representations of these deities/devas (hitxp.com).
Jesus as a Reincarnation of Mithra
It must have been a very old idea since traces of it are found in Buddhism and Vedic Hinduism. The Bodhisattva (buddha-to-be) is said to have descended from Tusita heaven to turn the wheel of the Dharma. And the future buddha, Maitreya, is said to reside there now waiting until such time as the Dharma is lost, leading to messianic expectations by many Mahayana Buddhists. The concept runs more deeply with frequent stories of Sakka -- the lord of lords and king of kings (namely, the chief of the Tavatimsa devas and the king of the Four Great Kings of Catumaharajika deva world) stepping down from "The Heaven of the Thirty-Three" (Tavatimsa) to intervene in human affairs, particularly to uphold its sense of morality.
(1) Mithra was born on December 25th as an offspring of the Sun. Next to the gods Ormuzd and Ahrimanes, Mithra held the highest rank among the gods [devas] of ancient Persia. He was represented as a beautiful youth and a mediator. Reverend J. W. Lake states: "Mithras is spiritual light contending with spiritual darkness, and through his labors the kingdom of darkness shall be lit with heaven's own light; the Eternal will receive all things back into his favor, the world will be redeemed to God. The impure are to be purified, and the evil made good, through the mediation of Mithras, the reconciler of Ormuzd and Ahriman. Mithras is the Good, his name is Love. In relation to the Eternal he is the source of grace, in relation to man he is the life-giver and mediator" (Plato, Philo, and Paul, p. 15).
(2) He was considered a great traveling teacher and master. He had 12 companions just as Jesus is said to have had 12 disciples. Mithras also performed miracles.
(3) Mithra was called "the good shepherd," "the way, the truth, and the light," "redeemer," "savior," and "Messiah." He was identified with both the lion and the lamb.
(5) Chambers Encyclopedia says: "The most important of his many festivals was his birthday, celebrated on the 25th of December, the day subsequently fixed -- against all evidence -- as the birthday of Christ. The worship of Mithras early found its way into Rome, and the mysteries of Mithras, which fell in the spring equinox, were famous even among the many Roman festivals. The ceremonies observed in the initiation to these mysteries -- symbolical of the struggle between Ahriman and Ormuzd (the Good and the Evil) -- were of the most extraordinary and to a certain degree even dangerous character. Baptism and the partaking of a mystical liquid, consisting of flour and water [sura, a kind of beer or brew the Asuras were fond of prior to being cast out of the Tavatimsa deva world], to be drunk with the utterance of sacred formulas [mantras, japa, or prayers], were among the inauguration acts."
(6) Prof. Franz Cumont, of the University of Ghent, writes the following concerning the religion of Mithra and the religion of Christ: "The sectaries of the Persian god, like the Christians', purified themselves by baptism, received by a species of confirmation the power necessary to combat the spirit of evil; and expected from a Lord's supper salvation of body and soul. Like the latter, they also held Sunday sacred, and celebrated the birth of the Sun on the 25th of December....They both preached a categorical system of ethics, regarded asceticism as meritorious, and counted among their principal virtues abstinence and continence, renunciation and self-control. Their conceptions of the world and of the destiny of Man were similar. They both admitted the existence of a Heaven inhabited by beatified ones [devas, literally, "shining ones"], situated in the upper regions [two spheres of spaece just above the Earth], and of a Hell, peopled by demons, situated in the bowels of the Earth. They both placed a flood at the beginning of history; they both assigned as the source of their condition, a primitive revelation; they both, finally, believed in the immortality of the soul [the ancient Indian concept of reincarnation], in a last judgment, and in a resurrection of the dead, consequent upon a final conflagration of the universe" (The Mysteries of Mithras, pp. 190, 191).
(7) Reverend Charles Biggs stated: "The disciples of Mithra formed an organized church, with a developed hierarchy. They possessed the ideas of Mediation, Atonement, and a Savior, who is human and yet divine [a deva or extraterrestrial on Earth], and not only the idea, but a doctrine of the future life. They had a Eucharist, and a Baptism, and other curious analogies might be pointed out between their system and the church of Christ (The Christian Platonists, p. 240).
(8) In the catacombs at Rome was preserved a relic of the old Mithraic worship. It was a picture of the infant Mithra seated in the lap of his virgin mother, while on their knees before him were Persian Magi [a.k.a., the Three Wise Men] adoring him and offering gifts.
(9) He was buried in a tomb, and after three days he rose again [all astrological details hinting at the origin of the myth, namely, that the real reference is to the alignment of celestial bodies and the planet Earth cyclically returning to life every spring, as explained in the original Zeitgeist movie]. His resurrection was celebrated every year.
(10) McClintock and Strong wrote: "In modern times Christian writers have been induced to look favorably upon the assertion that some of our ecclesiastical usages (e.g., the institution of the Christmas festival) originated in the cultus of Mithraism. Some writers who refuse to accept the Christian religion as of supernatural origin, have even gone so far as to institute a close comparison with the founder of Christianity; and Dupuis and others, going even beyond this, have not hesitated to pronounce the Gospel simply a branch of Mithraism" (Art. "Mithra").
(11) Mithra had his principal festival on what was later to become Easter, at which time he was resurrected [all recurring celestial, not historical, events]. His sacred day was Sunday, "the Lord's Day." The Mithra religion had a Eucharist or "Lord's Supper."
(12) The Christian Father Manes, founder of the heretical sect known as Manicheans, believed that Christ and Mithra were one. His teaching, according to Mosheim, was as follows: "Christ is that glorious intelligence which the Persians called Mithras...His residence is in the sun" (Ecclesiastical History, 3rd century, Pt. 2, Chp. 5).
"I am a star which goes with thee and shines out of the depths." - Mithraic saying
"I am the root and the offspring of David, and the bright morning star." - Jesus (Rev. 22:16)
December 25 is whose birthday?
There are three types of religions in the world today: ones that do not care to convert others and treat all religions equally (like Hinduism); ones that promote themselves without demoting other religions (like Buddhism); and ones that promote themselves by demoting others (like the Christianity spread by evangelists and missionaries).
Franz Cumont was the first scholar to observe the similarity between Christianity with Mithraism. He pointed out that Christianity borrowed iconographic themes from Mithraism...between the third and fifth centuries, not before that.
According to Cumont, the Christian story of Moses striking Mount Horeb (Sinai) with his staff to release drinking water was inspired by the earlier Mithraic reference to Mithras shooting arrows at rocks causing fountains to spring up. This again is a common event in the stories of Vedic deities in the ancient Indian texts. Read details about ancient Mithraism here.