God promised Abraham a Messiah, it was all God's idea from the beginning of time. Give the Author of Life some credit and the other philosophies just foreshadowed what was to happen.
In kippers that "Many scholars believe the eschatology of Judaism and possibly the idea of monotheism originated in Zoroastrianism, and may have been transferred to Judaism during the Babylonian captivity, thus eventually influencing Christian theology. Bible scholar P.R. Ackroyd states: "the whole scatologicalALcheme, however, of the Last Judgment, rewards and punishments, etc., within which immortality is achieved, is manifestly Zoroastrian in origin and inspiration." However, the theory is questioned by some mainstream historians and scholars. The Oxford History of the Biblical World states "There is little if any effect of Zoroastrian elements on Judaism in the Persian period.". Nevertheless scholars such as Soloman Nigosian contend, in regarding the similar ideas of Zoroaster and later Jewish writers, that ?the ideas were indigenous to Iran...it is hardly conceivable that some of the characteristic ideas and practices in Judaism, Christianity, and Islam came into being without Zoroastrian influence.? The new faith (Zoroastrianism) emerged in lager Persian empires. " Zoroastrianism reflected the cosmopolitan society of the empires". During this time Zoroastrianism profoundly effected the beliefs and values of Judaism, Christianity, and Islam"
However If anything it seems more likely that the new belief would be more likely to take on traits of an old belief in order to gain influence.
"allegations of an early Christian dependence on Mithraism have been rejected on many grounds. Mithraism had no concept of the death and resurrection of its god and no place for any concept of rebirth -- at least during its early stages...During the early stages of the cult, the notion of rebirth would have been foreign to its basic outlook...Moreover, Mithraism was basically a military cult. Therefore, one must be skeptical about suggestions that it appealed to nonmilitary people like the early Christians"-Ronald H. Nash
The Mithraic religion was constantly changing and adapting itself to the culture. This being the case, the most likely explanation for the myths about Mithra's' miraculous birth and his becoming a "savior god" were in all likelihood borrowed from Christianity. Though the cult started long before Christianity in Iran, there's no evidence of its presence in the Roman Empire during the first century when the original New Testament documents were being written. Part of the problem is due to the fact that the collection of Zoroastrian teaching was not completed until the fourth century C.E. [A.D.], leaving in some doubt who may have influenced whom in such matters.
Mithra was the Sun God, not the Son of God, and given the exclusivity nature of Christianity and the fact that Mithra-ism and Christianity did not overlap during the first century, any similarities between the two religions were most likely due to a later Christian influence on Mithra ism and not the other way around.
Given all the evidence, the claims that Christianity somehow borrowed from Mithraic beliefs is shown to be unsupported by fact. Many scholars now believe that it is Christianity's increasing popularity that caused a late form of Mithra-ism to change in order to sound more mainstream. However, at its core, Mithra-ism remains a pagan form of worship based on a superstitious and primitive worldview.
No , this is just another fable put forth by God haters. Christianity and its parent religion Judaism are the only true religions. Both are in reality the same truth . Christianity is the completed form of Judaism . All other religions including the 2 you mention are false.