Richard Foltz is Professor of Religion at Concordia University, Montreal. He is the author of several books, including Religions of the Silk Road (2nd edition, Palgrave Macmillan, 2010), in addition to many papers, encyclopedia articles and book chapters.

Since ancient times, Iranian religion has deeply influenced a number of the world's faith traditions, especially Christianity and late Judaism. In this helpful survey, historian of religion Foltz traces the history of religion in Iran and observes the ways that many faiths have incorporated many of its beliefs and practices. Ancient Iranian religion attributes the creation of the universe to cosmic forces. As Iranian religion evolved, Zoroastrianism—which developed as the major religion of Iran sometime between 1200 and 600 BCE—introduced the notion of a creator deity, Ahura Mazda, and its prophet, Zoroaster (or Zarathustra), who wrote down Ahura Mazda's words in the Avesta, or scriptures. As Foltz points out, Zoroastrianism developed a dualistic system of cosmic good and evil, a belief in personal resurrection, angelology and demonology, and eschatological notions about cosmic battles between the forces of light (good) and darkness (evil). Foltz devotes a chapter to the major world religions that have passed through, and in some cases still exist, in Iran. Although Iranian religion has famously influenced Christianity—particularly in the development of cosmic dualism—Foltz demonstrates that it has also shaped Islam, Buddhism, Manichaean Gnosticism, Judaism and the Baha'i faith. Although Foltz uncovers no new information, his straightforward history provides useful insights into the foundations of many of the world's religions.