Zoroastrianism

"Zoroastrianism is the oldest of the revealed credal religions, and it has probably had more influence on mankind, directly and indirectly, than any other single faith."

"Zoroastrianism survives today only among small communities in the province of Fars, and among the ninety thousand Parsees of India. These devotedly preserve and study the ancient scriptures, worship fire, earth, water and air as sacred, and expose their dead in “Towers of Silence” to birds of prey lest burning or burial should defile the holy elements. They are a people of excellent morals and character, a living tribute to the civilizing effect of Zarathustra’s doctrine upon mankind."

"Dualistic religions flourished for more than a thousand years. Sometime between 1500 BC and 1000 BC a prophet named Zoroaster (Zarathustra) was active somewhere in Central Asia. His creed passed from generation to generation until it became the most important of dualistic religions - Zoroastrianism. Zoroastrians saw the world as a cosmic battle between the good god Ahura Mazda and the evil god Angra Mainyu."

"The pantheon was never eliminated, and Zoroastrianism, in some sense at least, remained a polytheistic religion throughout its history, although today the many deities have lost their individual divine character and are not worshipped for themselves but have been reinterpreted as allegories or symbols. Thus, modern Zoroastrianism is probably best described as monotheistic, certainly as monotheistic as Christianity with its Trinity and angels, though less monotheistic than Judaism and Islam."

"Zoroastrians were a colony from Northern India...[who] migrated westward to Arachosia and Persia."