Adherents of Zoroastrianism are found throughout the world, with the largest populations residing in Iran and India. Approximately 18,000 Zoroastrians are found in North America, and as of 2007 around 250 reside in Georgia. Farrokh Mistree, a professor of mechanical engineering at the Georgia Institute of Technology, held a Zoroastrian open house shortly after his move to Atlanta in the early 1990s, and he soon built up a mailing list and instituted a monthly gathering of the new community. The Atlanta Zarathushti Association was established in Atlanta in May 2004 and constitutes the only Zoroastrian group in the state; most participants are immigrants from India, Iran, and Pakistan.
According to Zoroastrian teaching, at age thirty the prophet saw Ahura Mazda, the "Lord of Wisdom," who made the world in seven stages: sky, water, earth, plants, animals, humans, and fire. Humans, who have the capacity to choose good or evil, are regarded as Ahura Mazda's finest creation. Everyone is judged at death on the basis of his or her performance in life, and those who consistently choose good over evil in thought, word, and deed will be allowed to cross "the bridge of the separator" into heaven. The rest fall into hell. At the end of time, when evil is vanquished, the body and soul are brought together in a world that is in perfect harmony.
Zoroastrians cover their heads at prayer times and in temples where a sacred fire is lit. In addition, two items of clothing are symbolic of the faith: the sudra, a white undershirt with a pocket for storing good deeds; and the kusti, a sacred cord braided from six strands, each composed of twelve white woolen threads with tassels on the end. The cord is lapped three times around the waist over the shirt and is untied and retied each morning and before prayers and meals.
Zoroastrianism teaches moderation in food and drink. Among very observant Zoroastrians, food, utensils, and dishes are prevented from coming into contact with products removed from the body, such as hair, nails, saliva, or blood.
In addition to his prominence within the Zoroastrian narrative, Zarathushtra also famously appears in the work of Friedrich Nietzsche, the nineteenth-century German philosopher and author of Thus Spake Zarathustra: A Book for All or None, a fictitious account of the prophet's life and teachings. Composed in the 1880s, after the publication of Nietzsche's well-known proclamation that "God is dead," Thus Spake Zarathustra introduces the concept of the "superman," in which the development of an ideal humanity supplants the need for a deity.