The universe is the battleground that is divided into three sections: the upper world, which is bathed with light; the earth; and the underworld, which is blanketed with darkness. The opponents are Ahura Mazda and Ahriman, with Ahura Mazda representing the good force and Ahriman representing the bad. The battle will last till Ahura Mazda defeats Ahriman in the year 12,000 (we are now presumably around 11,500). In accordance with Zoroaster's teachings and beliefs, this battle represents the world and its future. Ahura Mazda created this world as a trap for Ahriman. Ahriman gains strength by human beings" actions of evil. He is weakened by the people's choice of good over evil. Ahriman will then enter Ahura Mazda's world, and if weakened enough, Ahura Mazda would be able to destroy him.
In the beginning, as Ahriman attempts to kill Ahura Mazda, he is stopped and pulled away. Both of the Gods agree to a period of peace that will last 9,000 years. During the first three thousand years Ahura Mazda creates angels, good spirits and Fravashis. These Fravashis are the original heavenly images of men living in the upper world. During the next three thousand years the Fravashis come down to earth. There they lead a perfect sinless life. Ahriman is angry because of the advantage he sees the Ahura Mazda has gained over him in preparation for the final battle. He tries to bring evil to the world, but he is rendered powerless by the sacred Ahunavairya formula that Ahura Mazda utters. .
In the next three thousand years Ahriman invades the world. He kills the early men and animals and disperses demons throughout the world. However a human couple arises from the seed of the early man and a cow from the seed of early animal. These beings are mixed and must choose between the good and evil that now inhabits the world.
The final three thousand year period begins and Ahura Mazda sends Zoroaster down to the world.
