Zoroastrianism, or Mazdayasna, is one of the world's oldest religions that remains active. It is a monotheistic faith (i.e. a single creator God), centered in a dualistic cosmology of good and evil and an eschatology predicting the ultimate destruction of evil. Theology. Zoroastrians believe that there is one universal, transcendent, supreme God, Ahura Mazda, or the "Wise Lord". (Ahura means "Being" and Mazda means "Mind" in a sacred Old Iranian language called Avestan). Zoroaster, also known as Zarathustra, Zarathushtra Spitama or Ashu Zarathushtra, was an ancient Iranian-speaking spiritual leader and ethical philosopher who taught a spiritual philosophy of self-realization and realization of the Divine. The Faravahar also known as Farr-e Kiyani is the most common symbol of Zoroastrianism. This emblem is said to represent the way people on earth should live.