This is part 1 of the Historical Jesus series. You can read part 3 here.
Zoroastrianism is considered by some skeptics to be the coup de gras to the originality of the Christian faith. Rather than challenging the well-attested life and resurrection of Christ outright, Zoroastrianism challenges the originality of biblical teachings in the Old and New Testaments.
The first problem with these claims goes back to the primary sources of Zoroastrianism. Yamauchi explains in his book Persia and the Bible:
The Zoroastrian texts are rather disparate and, with one exception, relatively late. They are limited and difficult sources to utilize for a reconstruction of Persian religion. Richard Frye compares an Iranologist’s task to a situation where a student of Judaism has only the Psalms, fragments of the Talmud, and later writings as sources for reconstructing the history of ancient Jewish religion.”
Many of the alleged borrowings from Zoroastrianism took place prior to the New Testament era. In a direct challenge to the faith, proponents of the Zoroastrian influence on Christianity state that Zoroastrianism holds the biblical origins of monotheism, sin, salvation, a redeemer, and bodily resurrection. Let us take these challenges in turn.
Monotheism was most likely not taught by Zoroastrianism. Instead, it taught either henotheism (where one god is exalted over lesser gods) or dualism. Mary Boyce, who was one of the world’s foremost experts on Zoroastrianism, explains that Zoroastrian monotheism is difficult to affirm because “the character of every known Old Iranian religion appears polytheistic; and no declaration of the existence of one God, and one God alone, can be found in any source, not even in the utterances of Zoroaster.” Many experts believe that Zoroaster taught a form of dualism, which Willard Oxtoby defines as “a conception of the universe which postulates two ultimate principles, seen as opposed to each other and more or less evenly matched.” Essentially, it is a battle between two uncreated primordial spirits, one good (God), and one evil. The Bible, however, never affirms dualism. There is good and evil, but God is unquestionably sovereign over all. God is the only uncreated being, or “maximally great being” in existence. Moreover, in Zoroastrianism, God is not omnipotent. Rather, as Yamauchi explains, “Only with the help of men who choose his side will God triumph over the Evil One in the end.” Yet the Bible is clear that God does not need us (rather, we need Him!) and that He will triumph in the end, not because of us but for us.
In opposition to the doctrine of original sin in which all of humanity inherits a sin nature from Adam, Zoroastrianism teaches that there is no inherited sin nature. A person is either just or sinful by freely choosing whether to be good or evil. If they do become evil and require salvation, then this is equally an issue of the will. Salvation in Zoroastrianism is not a gift of God attained by grace through faith; rather, Zoroastrian salvation is works-based, an idea that the New Testament strongly rejects. Zoroaster taught that salvation was completely dependent upon man’s good works outweighing his bad and, according to Boyce, “There could be no intervention, whether compassionate or capricious, by an omnipotent Being to alter their consequence.” While later Zoroastrianism did begin creating and incorporating rites of repentance, these are in direct conflict with the words of Zoroaster concerning man achieving his own salvation.
The word translated “redeemer” in Zoroastrian writings—Saoshyant—is not one who saves people from sin and guilt but is rather one who comes as a benefactor. Some scholars believe that saoshyant referred to Zoroaster himself or they believe that the term as used in the Gathas (the most important and authoritative Zoroastrian scriptures) refers more to future benefactors who will help Zoroaster bring final restoration in the end times (recall that Zoroaster will not be able to triumph over evil on his own in the end but will require the help of others). Furthermore, as Jacques Duchesne-Guillemin explains, “Zoroaster did not give himself out to be the redeemer. When his prayers call the redeemer who is to renew existence, he means the prince who shall accept his doctrine and realize the Dominion of Righteousness and Good Mind. He even allows the role of redeemer to any man, provided he practices righteousness.” This is vastly different from the foreknown, predestined, and eternal God-Man, Jesus Christ of the New Testament.
Lastly, as Yamauchi states assuredly, “There is no certain affirmation of a belief in a resurrection by Zoroaster in the Gathas.” He continues, “Yashna 34.14 is sometimes cited for such a belief, but this clearly refers to bodily prosperity in this life.” The most clear references to resurrection appear in Pahlavi Bundahishn, which discuss resurrection after the appearance of the final saoshyant and the final judgment (when fire will melt all metal found in the hills and mountains and purify all souls, both righteous and wicked). This is barely similar to the biblical account of Christ’s Second Coming and Judgment Day, but there is another reason to be skeptical of its influence upon Christianity: the Pahlavi scriptures were not composed until the ninth and tenth centuries AD. Therefore, William Malandra, an expert on ancient Iranian religion, recommends exercising caution, explaining that the Pahlavi scriptures “must be used with extreme care as evidence for the earlier forms of the religion.”
This is part 5 of the Historical Jesus series. You can read part 5 here.
Instead of a having comments section, we invite you to contact us here.
 Edwin M. Yamauchi, Persia and the Bible (Grand Rapids, MI: Baker, 1996), 403.
 Many, for instance, try to make the claim that Zoroastrianism had an influence on Judaism that found its way into the Hebrew scriptures, thus shaping Christianity through the mediation of the Old Testament.
 Mary Boyce, “On Mithra’s Part in Zoroastrianism,” Bulletin of the School of Oriental and African Studies, University of London 32, no. 1 (1969): 18. http://www.jstor.org.ezproxy.tiu.edu/stable/613386. Quoted in Yamauchi, 437.
 Willard Oxtoby, World Religions: Western Traditions (Oxford: Oxford University Press, 1996), 536. Quoted in Yamauchi, 438.
 Yamauchi, 439.
 Mary Boyce, The Early Period. Vol. 1 of A History of Zoroastrianism (New York: Brill, 1996),246. Quoted in Yamauchi, 443.
 Yamauchi, 444.
 Jacques Duchesne-Guillemin, The Hymns of Zarathustra (Boston: Beacon, 1963), 19. Quoted in Yamauchi, 444.
 Yamauchi, 456.
 Ibid., 456-57.
 Ibid., 409.
 William W. Malandra, ed. and trans., “Preface” in An Introduction to Ancient Iranian Religion: Readings from the Avesta and the Acheimenid Inscriptions (Minneapolis: University of Minnesota Press, 1983), vi. Quoted in Yamauchi, 409.