Zoroaster (Old Persian: Zarathustra, in modern Persian Zardosht) is generally thought to have lived about the 11th or 10th century BCE. Zoroastrianism is a religion and philosophy based on the teachings of Zoroaster as prophet. The term Zoroastrianism is, in general usage, essentially synonymous with Mazdaism (the worship of Ahura Mazda, exalted by Zoroaster as the supreme divine authority). In Zoroastrianism, the Creator Ahura Mazda is all good, and no evil originates from Him. Thus, in Zoroastrianism good and evil have distinct sources, with evil (druj) trying to destroy the creation of Mazda (asha), and good trying to sustain it. In some form, it served as the national- or state religion of a significant portion of the Iranian people for many centuries.