During the glory years of the powerful Persian Empire, a new religion arose to challenge the polytheism of earlier times. Tradition dates its Persian prophet, Zarathustra (Zoroaster to the Greeks), to the sixth or seventh century B.C.E., although some scholars place him hundreds of years earlier. Whenever he actually lived, his ideas took hold in Persia and received a degree of state support during the Achaemenid dynasty (558–330 B.C.E.). Appalled by the endemic violence of recurring cattle raids, Zarathustra recast the traditional Persian polytheism into a vision of a single unique god, Ahura Mazda, who ruled the world and was the source of all truth, light, and goodness. This benevolent deity was engaged in a cosmic struggle with the forces of evil, embodied in an equivalent supernatural figure, Angra Mainyu. Ultimately this struggle would be decided in favor of Ahura Mazda, aided by the arrival of a final savior who would restore the world to its earlier purity and peace. At a day of judgment, those who had aligned with Ahura Mazda would be granted new resurrected bodies and rewarded with eternal life in Paradise. Those who had sided with evil and the “Lie” were condemned to everlasting punishment. Zoroastrian (zohr-oh-ASS-tree-ahn) teaching thus placed great emphasis on the free will of humankind and the necessity for each individual to choose between good and evil.

The Zoroastrian faith achieved widespread support within the Persian heartland, although it also found adherents in other parts of the empire, such as Egypt, Mesopotamia, and Anatolia. But it never became an active missionary religion and did not spread widely beyond the region. Alexander the Great’s invasion of the Persian Empire and the subsequent Greek-ruled Seleucid dynasty (330–155 B.C.E.) were disastrous for Zoroastrianism, as temples were plundered, priests slaughtered, and sacred writings burned. But the new faith managed to survive this onslaught and flourished again during the Parthian (247 B.C.E.–224 C.E.) and Sassanid (224–651 C.E.) dynasties. It was the arrival of Islam and an Arab empire that occasioned the final decline of Zoroastrianism in Persia, although a few believers fled to India, where they became known as Parsis (“Persians”). The Parsis have continued their faith into present times.

Like Buddhism, the Zoroastrian faith vanished from its place of origin, but unlike Buddhism, it did not spread beyond Persia in a recognizable form. Some elements of the Zoroastrian belief system, however, did become incorporated into other religious traditions. The presence of many Jews in the Persian Empire meant that they surely became aware of Zoroastrian ideas. Many of those ideas—including the conflict of God and an evil counterpart (Satan); the notion of a last judgment and resurrected bodies; and a belief in the final defeat of evil, the arrival of a savior (Messiah), and the remaking of the world at the end of time—found a place in an evolving Judaism. Some of these teachings, especially the concepts of heaven and hell, later became prominent in those enormously influential successors to Judaism—Christianity and Islam.11 Thus the Persian tradition of Zoroastrianism continued to echo well beyond its disappearance in the land of its birth.