Zoroastrian cosmology is divided in four periods of 3,000 years. Zoroaster was born in the beginning of the fourth period, to be succeeded at the end of each next millennium by a new saviour. When Saoshyant, the third and last saviour would come the last judgment and the creation of a new world.
Creation of the universeEdit
According to the Zoroastrian story of creation, Ahura Mazda existed in light and goodness above, while Angra Mainyu existed in darkness and ignorance below. They have existed independently of each other for all time, and manifest contrary substances. Ahura Mazda first created seven abstract heavenly beings called Amesha Spentas, who support him and represent beneficent aspects, along with numerous yazads, lesser beings worthy of worship. He then created the universe itself in order to ensnare evil. Ahura Mazda created the floating, egg-shaped universe in two parts: first the spiritual (menog) and 3,000 years later, the physical (getig). Ahura Mazda then created Gayomard, the archetypical perfect man, and the first bull.
While Ahura Mazda created the universe and mankind, Angra Mainyu, whose instinct is to destroy, miscreated demons, evil yazads, and noxious creatures (khrafstar) such as snakes, ants, and flies. Angra Mainyu created an opposite, evil being for each good being, except for humans, which he found he could not match. Angra Mainyu invaded the universe through the base of the sky, inflicting Gayomard and the bull with suffering and death. However, the evil forces were trapped in the universe and could not retreat. The dying primordial man and bull emitted seeds. From the bull's seed grew all beneficial plants and animals of the world, and from the man's seed grew a plant whose leaves became the first human couple. Man thus struggles in a two-fold universe trapped with evil. The evils of this physical world are not products of an inherent weakness, but are the fault of Angra Mainyu's assault on creation. This assault turned the perfectly flat, peaceful, and ever day-lit world into a mountainous, violent place that is half night.