The roots of Zoroastrianism are thought to have emerged from a common prehistoric Indo-Iranian religious system dating back to the early 2nd millennium BC. The prophet Zoroaster himself is thought by many modern historians to have been a reformer of the polytheistic Iranian religion who lived in the 10th century BC. [Wikipedia]The central deity of Zoroastrianism is Ahura Mazda (‘Lord of Wisdom’). Ahura Mazda is in continuous conflict with his negative counterpart Angra Mainyu (‘Destructive Spirit’).
Although Zoroastrians do not consider Angra Mainyu* to be equivalent in strength to Ahura Mazda, the religion is sometimes regarded as dualistic because of this conflict between good and evil. A more obviously dualistic religion is Manichaeism, which for a time replaced Zoroastrianism as the dominant religion in Persia, and which adopted the figures of Ahura Mazda and Angra Mainyu but posited them to be of roughly equal power. (A better word for what is meant may be ditheism rather than dualism.)
Zoroastrian belief includes the concept of an end of the world, or eschatology, although ‘end’ should be understood to mean radical transformation rather than complete cessation.
At the end, there will be a great battle between the forces of good and those of evil in which the good will triumph. On earth, the Saviour will bring about a resurrection of the dead. This is followed by a last judgment through ordeal. The forces of good will cause the metal in the mountains to melt, and to flow across the earth like a river. All mankind — both the living and the resurrected dead — will be required to wade through that river, but for the righteous it will seem to be a river of warm milk, while the wicked will be burned.
There will be a final act of worship involving the preparation of parahaoma, a sacred liquid used in Zoroastrian rituals. The righteous will partake of the parahaoma, which will confer immortality upon them. Thereafter, humankind will become divine entities, living without food, without hunger or thirst, and without possibility of bodily injury.
All humanity will speak a single language and belong to a single nation without borders. All will share a single purpose and goal, joining with the divine for a perpetual exaltation of God’s glory. [Wikipedia text, edited]
* Angra Mainyu is also known as ‘Ahriman’.
** Thumbnail is of a painting by Anuki Natsvlishvili, ‘Ahura Mazda & Ahriman’, viewable at saatchiart.com. It shows Ahura Mazda, on the left, in battle with Ahriman, on the right.