Frashokereti

Frashokereti (frašō.kərəti) is the Avestan language term (corresponding to Middle Persian frašagird <plškrt>) for the Zoroastrian doctrine of a final renovation of the universe, when evil will be destroyed, and everything else will be then in perfect unity with God (Ahura Mazda). The name suggests "making wonderful, excellent".

The doctrinal premises are (1) good will eventually prevail over evil; (2) creation was initially perfectly good, but was subsequently corrupted by evil; (3) the world will ultimately be restored to the perfection it had at the time of creation; (4) the "salvation for the individual depended on the sum of [that person's] thoughts, words and deeds, and there could be no intervention, whether compassionate or capricious, by any divine being to alter this." Thus, each human bears the responsibility for the fate of his own soul, and simultaneously shares in the responsibility for the fate of the world.

The eschatological ideas are only alluded to in the surviving texts of the Avesta, and are known of in detail only from the texts of Zoroastrian tradition, in particular in the ca. 9th century Bundahishn. The accompanying story, as it appears in the Bundahishn (GBd 30.1ff), runs as follows: At the end of the "third time" (the first being the age of creation, the second of mixture, and the third of separation), there will be a great battle between the forces of good (the yazatas) and those of evil (the daevas) in which the good will triumph. On earth, the Saoshyant will bring about a resurrection of the dead in the bodies they had before they died. This is followed by a last judgment through ordeal. The yazatas Airyaman and Atar will melt the metal in the hills and mountains, and the molten metal will then 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 (ashavan) it will seem to be a river of warm milk, while the wicked will be burned. The river will then flow down to hell, where it will annihilate Angra Mainyu and the last vestiges of wickedness in the universe.

...
Wikipedia