There is only one religion, though there are a hundred versions of it.
George Bernard Shaw, Plays Pleasant and Unpleasant, Vol. II, preface (1898)
Zoroastrianism is the religion and philosophy based on the teachings ascribed to the prophet Zoroaster. While Zoroastrianism was once the dominant religion of much of Greater Iran, the number of adherents has dwindled to less than 200,000 worldwide, with concentrations in India and Iran. (Information source: Wikipedia).
