Zoroastrianism is a religion and philosophy based on the teachings of prophet Zoroaster (aka Zarathustra, in Avestan) founded in the early part of the 5th century BCE. The term Zoroastrianism is, in general usage, essentially synonymous with Mazdaism, i.e. the worship of Ahura Mazda, exalted by Zoroaster as the supreme divine authority. The political power of the pre-Islamic Iranian dynasties lent Zoroastrianism immense prestige in ancient times, and some of its leading doctrines were adopted by other religious systems. The Faravahar (or Ferohar) is one of the primary symbols of Zoroastrianism; nowadays it is said to be a reminder of one's purpose in life, which is to live in such a way that the soul progresses towards frasho-kereti, or union with Ahura Mazda, the supreme divinity in Zoroastrianism. and is believed to be the depiction of a Fravashi (guardian spirit).