Did New Testament Christianity borrow from ancient pagan mystery cults such as Mithraism? Attempts have been made to discredit Christianity or to cast doubt upon its veracity by alleging that it simply borrowed its ideas from the Mithraic mystery religion. For this allegation to have substance, one must prove: 1.) That Mithraism predates Christianity; 2.) Minimally, that adherents of Mithraism had direct contact with the stories, rituals, and beliefs to clearly display real and significant parallels, and that there are no better candidates that serve as a model for understanding nascent Christianity, and 3.) Maximally, that there is an oral or literary dependence of the latter on the former.
Can advocates of New Testament dependence upon Mithraism establish points one through three above? First, archaeology indicates that the earliest Mithraic temples or mithraeum in the Roman Empire post-date the rise of Christianity by over a century. The earliest known Mithraic inscription also dates to the second century. Christianity cannot be dependent upon Mithraism because there is no evidence for the Mithraic mysteries prior to A. D. 100. Furthermore, when evidence for the mystery religion begins to appear, it is almost entirely absent from Judea or Palestine where the New Testament was composed and the core doctrines of Christianity were formulated. The only mithraeum discovered in Palestine dates to the fourth century. Christianity could not have borrowed its teachings from Mithraism because Christianity antedates the Mithraic mystery religion in the Roman Empire.
Second, alleged parallels between Christianity and the practices of Mithraism are greatly exaggerated. Modern advocates of Mithraic parallels allege that Mithra experienced a virgin birth, died in a manner similar to Christ, and rose from the dead. Christianity also allegedly borrowed baptism and the Lord’s Supper from Mithraism.
However, Mithraic art never depicts a virgin birth for Mithra. He springs naked from a rock, or alternatively the zodiac, or an egg, while holding a torch and a knife. Furthermore, no clear references to the death of Mithras can be found in either Mithraic art or surviving literary sources. Just as there is no evidence for the death of Mithras, there is no evidence for his resurrection, for the latter is inconceivable without the former. The concept of rebirth (cf. John 3:3) is also absent from early Mithraism. The gradual identification of Mithras with Sol takes place too late to have any impact on early Christianity, as does the belief in an astrological ascent of the soul.
Is Mithraism the source for the Christian ordinance of baptism, the immersion of the believer in water as a sign of Christ’s death, burial, and resurrection? On rare occasions, post-Christian Mithraism practiced a ritual bath in the blood of a bull, but since this practice did not exist in the religion before A. D. 160, all extant references to it were in parts of the Roman empire in the west, far removed from Palestine, and the ritual bath included no notion of a death and resurrection, allegations that this practice was the source of Christian baptism are not credible. Does Mithraism provide the source for the ordinance of the Lord’s Supper? While a common meal was practiced as a rite in Mithraism, parallels to the Christian practice of the Lord’s Supper are extremely questionable. First, there is no evidence that the Mithraic communal meal was practiced by all initiates. Second, bread eaten at the Mithraic meal represented the blood of a bull slain by Mithra in hunting, not the blood of Mithra himself. There is no evidence at all of Christian dependence upon the Mithraic common meal, and parallels between the Christian communion rite and Mithraism are, at best, highly tenuous and dubious.
It is true that the date for the Christmas holy day as celebrated in Roman Catholicism was adopted from paganism, as were the dates of many other Roman Catholic holy days. However, the Bible never affirms that December 25 was the birthday of the Lord Jesus Christ, nor was Christmas brought into the developing Catholic religion until centuries after the death and resurrection of Jesus Christ, the composition of the New Testament, and the crystallization of Christian doctrine. It is one thing to demonstrate pagan influence upon Roman Catholicism centuries after the rise of Christianity when the Roman Catholic religion united with the Roman government. It is quite another to demonstrate pagan origins for Biblical Christianity itself.
In summary, the issue of Christian borrowing from Mithraism hinges on the issue of chronology. If the chronological priority of Mithraism is shown to be wrong, the entire issue is a moot point. Strong evidence indicates that the development of Mithraism in the Roman Empire was chronologically later, not earlier, than the advent of Christianity. Furthermore, even apart from the tremendous chronological problem, a causal connection would need to be established to prove that Christianity took its doctrines from Mithraism. To posit such a connection contradicts the facts of history. Finally, a careful look at proposed similarities between Mithraic stories and rituals and Christianity demonstrates that clear exaggeration has taken place by advocates of parallelism.
Rather than highly dubious parallels with Mithraism explaining the background and doctrines of Christianity, Christianity had its birth and development within the context of first century Judaism. Unlike the mythical god Mithras, the life of the historical Jesus is documented extremely well, and every key event in His life fulfills predictions in the Hebrew Scriptures. Rather than being a product of pagan mythology, the New Testament records historically accurate events through which the Lord Jesus Christ fulfilled the Old Testament prophecies of the coming Messiah.
As for the rituals and traditions of the early church, they too had their source in the one culture that had the most direct impact on early Christianity, Judaism. The initiation of the Lord’s Supper was in the direct context of the Jewish Passover meal. The sacrificial aspect of the death of Christ should likewise be understood in light of temple sacrifice, and Old Testament images of the substitutionary atonement and the scapegoat. As for origins of the Christian baptism, one need look no further than first century Judaism and the ministry of John the Baptist.
The idea that the New Testament borrowed or was dependent upon pagan mystery cults such as Mithraism is clearly a radically inaccurate evaluation of the historical data. Rather than the life of Christ and the records of the New Testament being legendary accounts because of their alleged dependence on Mithraism, the idea that Mithraism is the source of Biblical Christian doctrine and practice is itself a legend and a fable, no more real than the mythical god Mithra himself.
This study can also be accessed here.
 The following study is greatly abridged from “The Mithraic Cult and Christian Origins,” Allan Di Donato, Christian Apologetics Journal, Vol. 6, No. 1, Spring 2007, 21-53. The 167 footnotes in the original article provide extensive evidence from ancient sources. Professor Donato is an instructor in Humanities at a State college in Charlotte, NC.
 Compare the resources on the unbiblical and unauthoritative nature of Catholic holy days at http:/faithsaves.net/ecclesiology/.