The prophet of Zoroastrianism was Zoroaster, who may have lived as far back in time as 1000 B.C. or even 1400. Zoroastrian scripture is the Avesta.
Zoroaster rejected the old Persian gods and in their place believed that a single, omniscient, omnipresent, and omnipotent god, Ahura Mazda, ruled and created the world. Ahura Mazda and his helping spirits, the ahuras, fought against the prince of evil, Ahriman or Angra Mainyu and the daevas (evil). This makes Zoroastrianism, the religion of Zoroaster, dualistic. Followers of Zoroastrianism are supposed to help Ahura Mazda by being good in order to establish paradise on earth. A savior (saoshyant) and an afterlife with judgment and resurrection, are other elements of Zoroastrianism, according to A Dictionary of Asian Mythology. Death is the work of Ahriman; the soul, of Ahura Mazda.
Zoroastrianism is still practiced, especially in India and Iran, by the Parsis.
See Frequently asked questions on Zoroastrianism and the Avesta
References:
- "Dualism in Iranian and Christian Traditions"
François de Blois
Journal of the Royal Asiatic Society, Third Series, Vol. 10, No. 1 (Apr., 2000), pp. 1-19 - BBC Religion - Zoroastrianism
- Zoroastrians: Their Religious Beliefs and Practices, by Mary Boyce
Zoroaster is on the list of Most Important People to Know in Ancient History.
The German philosopher Nietzsche wrote Also Sprach Zarathustra 'Thus Spake Zarathustra,' which contains the statement "God is dead."
The Oxford Dictionary of Philosophy lists Mithraism and Manichaeanism as offshoots of Zoroastrianism.

