Zoroaster founded a new faith, which featured a dual godhead, an idea that has affected both Judaism and Christianity.

Ditheism, or belief in two gods as in Zoroastrianism, attempts to provide a satisfactory answer to one of the serious problems of religion: the explanation of evil. To some extent the concept of a dual godhead has penetrated both Judaism and Christianity. The god of darkness or evil found its way into the former in attenuated fashion in the form of Satan. The Dead Sea Scrolls, for instance, speak of the war between the sons of light and the sons of darkness. In Christianity, the force of evil becomes the Devil. Zoroaster
Vishtaspa

Zoroastrian ditheism was a theological position reached only with difficulty. The religion was developed by Indo-Europeans who wandered into the Iranian plateau about 2000 b.c.e. and reflects to a great extent the environment of the old religion before the invasion.

Zoroaster may have been the son of a landed proprietor. His name seems derived from a Greek corruption of the old Iranian word Zarathustra, possibly meaning “one who plows with camels” or “one whose camels are old.” According to tradition, at the age of twenty, Zoroaster left home to ponder religious questions and, after ten years, was rewarded with a series of revelatory visions in which an angel called him to ascend a mountain as a disembodied soul to meet with the old Iranian god Ahura Mazda and his heavenly host. In eight days, he was fully instructed as the god’s new prophet in the doctrines and duties of true religion. For ten more years, his preaching bore no tangible results beyond the conversion of his cousin, even though he inveighed against religious inadequacies and the social injustices visited on peasants and herdsman.

His first important conversion, of a prince named Vishtaspa, came at a crucial time when he needed support in his struggle with the Magi, the entrenched priests of the traditional cults. When Vishtaspa contributed his influence to the new religion, the whole court was converted. For the next twenty years, Zoroaster propagated the new faith, but its greatest success came only after his death at seventy-seven, victim of an assassin in a religious uprising. Darius the Great might have been the first Achaemenid converted. In general, however, the Persian kings were never militant supporters of the religion.

Zoroaster’s message was reasonably simple: He was Ahura Mazda’s prophet sent to teach religion and the end of the world. Worship was to be directed toward this one god who brought everything into existence and who in a final apocalyptic event would crush evil forever and establish right and truth. Ahura Mazda was said to express his will through the Holy Spirit, Spenta Mainyu, and various “modes” of divine action, such as good thought, power, prosperity, piety, and immortality. Just how Zoroaster envisaged these modes is difficult to say. As forces in their own right, as good genii, or angels, or as personalized abstractions, they represented a compromise with the local polytheism, a concession that makes it debatable whether Zoroaster was altogether a monotheist. Although Ahura Mazda was supreme, he was not unopposed. A polarity implicit in creation characterized all existence. Over against right, Asha, stood the lie, Druj; truth was confronted with falsehood, life with death, the good spirit by the bad.

Zoroaster’s cardinal principle of ethics taught that each person’s soul was the seat of war between good and evil. At creation, Ahura Mazda gave each person the freedom to determine his or her own actions and the power to choose between right and wrong. Good people would naturally accept the true religion, while the evil, especially those who continued to practice old rites, would reject it. The old local sacrifices were eliminated, and rituals were purged of what Zoroaster termed magic and idolatry. The sacred fire was kept, but only as a symbol of Ahura Mazda and not as an object of worship in itself. Zoroaster believed in individual judgment after death, with the state of the soul remaining fixed until a general resurrection at the end of the world when evil would be destroyed forever. Those whose record of evil was greater than their good report would dwell in the House of the Lie, Zoroaster’s hell, while the righteous would go to the House of Song, or paradise.

With the popularization of Zoroastrianism, more compromises entered into its original “monotheistic” theology. Moreover, the old Magi succeeded in molding a syncretistic system out of Zoroaster’s teaching and the old Iranian polytheism. Old Aryan gods were raised to a prominence far greater than the old modes. Thus Mithra was elevated along with a female figure, Anhita, the Spotless One, a counterpart of Ishtar, the goddess of fertility, to form a trinity: Ahura Mazda, Mithra, and Anhita. Zoroaster was raised from human status to that of a godlike personage. His coming was said to have been foretold for three thousand years. His birth became miraculous through Ahura Mazda’s intervention, and he became celebrated as an outstanding miracle worker.

Spells and formulas again became popular to ward off evil, and ceremonial purity took more and more precedence over inward regeneration. Eventually Zoroastrianism became a religion of a book, the Avesta (1000-600 b.c.e.), a collection of hymns broken into five parts—Yasna, Yasht, Wispered, Vendidad, and Khorde—that were once part of a far larger literature that has since disappeared. Zoroaster’s hymns, the Gathas, are in the Yasna; they are less legalized and simpler than the later writings.

Eventually in the Sāsānian period, the ditheism developed fully. The many contending gods were again demoted, and a god of evil rose in importance to contend Ahura Mazda’s monopoly. Although Zoroaster had spoken bitterly, but not very tangibly, of the evil spirit Shanitin or Satin, his successors rendered this figure more concrete in the form of an almost equal opponent of Ahura Mazda, the archfiend Ahariman, the cause of darkness and evil straining to nullify every good Ahura Mazda arranged, whether by killing frost in winter, excessive heat in summer, snakes, locusts, or by disbelief and death.

The impact of Zoroastrianism on the West is difficult to assess. The old Iranian god Mithra, greatly “Zoroastrianized,” became popular in the early Roman Empire; Gnosticism and Manichaeanism appear to owe some debt to the Zoroastrianism of the Sāsānian period.

• Bausani, Alessandro. Religion in Iran: From Zoroaster to Baha’ullah. New York: Bibliotheca Persica Press, 2000. An overview of the religions of Iran, which touches on Zoroastrianism.
• Boyce, Mary. Zoroastrians: Their Religious Beliefs and Practices. 1979. Reprint. New York: Routledge, 2001. A study of the followers of Zoroastrianism that includes a history of the belief.
• Clark, Peter. Zoroastrianism: An Introduction to an Ancient Faith. Sussex, England: Sussex Academic Press, 1999. Examines all aspects of Zoroastrianism, from its history to present.
• Hartz, Paula R. Zoroastrianism. New York: Facts on File, 1999. An overview of the religion.
• Kellens, Jean, ed. Essays on Zarathustra and Zoroastrianism. Costa Mesa, Calif: Mazda, 2000. A collection of essays on Zoroastrianism that cover topics such as the Avesta and specific beliefs.
• Kriwaczek, Paul. In Search of Zarathustra: The First Prophet and the Ideas That Changed the World. London: Weidenfeld and Nicolson, 2002. Focuses on Zoroaster and how his beliefs influenced those who came after him.
• Neusner, Jacob. Judaism and Zoroastrianism at the Dusk of Late Antiquity: How Two Ancient Faiths Wrote Down Their Great Traditions. Atlanta: Scholars Press, 1993. A comparison and contrast of Zoroastrianism and Judaism in antiquity.
• Nigosian, Solomon A. The Zoroastrian Faith: Tradition and Modern Research. Toronto: McGill-Queens University Press, 1993. This study looks at the Zoroastrian religion, examining the traditions and legends as well as scholarly research.

Darius the Great; Zoroaster. Zoroastrianism