Origins of the Millennial Idea
The word millennium derives from the Vulgate Bible, and translates the Greek chilias from the New Testament Book of Revelation (ch. 20) for the number One Thousand, that is, the One Thousand Years of Christ's Rule at the End of the Known Order. This number and the reign itself are quite mysteriously and symbolically presented, but they obviously reflect a vision of the conquest of God's goodness over evil. Already in Antiquity there had been comparable visions of a final cosmic denouement, which would explain why Revelation was appealing and intelligible enough in its time. There were dreamt hopes for the future, many of them embodied in prophetic and apocalyptic writings, which were eschatological, that is, projecting the Last Events of Time, such as the destruction of evil, the resurrection of the dead, and a final divine judgement. Countless ideas and movements have arisen in response to such visions, and these make up the history of what has come to be called millenarism, millenarianism, millennialism, or chiliasm.These terms are now used typologically in scholarly, especially social scientific literature, to denote expectations of a total or immense transformation of the cosmos, usually supposed to come suddenly and with final or ultimate consequences for humanity.
Nobody really knows when such visioning began. Aside from specific appeals to a temporal notion of "a thousand" connected to the Last Things - a thousand generations in the Deads Sea Scrolls, a thousand years in Revelation - the hope for some great consummation could well go back to ca 2000 BCE, if that indeed was when Zarathustra -was purveying his messages in the poetic Gathas in Avestan (there are disputes over dates and also over which materials in the "Zend-Avesta" go back to Zarathustra). Be scholarly debates as they may, the indications in the Gathas that humans are caught in a struggle between good and evil that will some day be resolved cosmically takes us back to the origins of the millennial idea typologically.
Biblical insights about the special purpose of Israel in covenanting with the one God do not at first entail a cosmo-eschatological vision, although for the first time in human thought we have the idea that "history" (= the story of Israel's ongoing relationships with Yahweh) is going somewhere (this being perhaps the most influential idea in the history of the world - usually but not always as conceived in religious terms). Israel's directionalism and Zoroastrian hopes for a cosmic solution were bound to meet (which they doubtless did under the Persian empire).Certainly the orientations chimed. We cannot say whose systematic formulations of eschatology came first, because Jewish apocalyptic texts (e.g Daniel) are to be dated earlier than the Zoroastrian ones we have to hand (e.g., Bundahishn), but the likelihood of imaged futures at least bouncing off and influencing each other is there (and the Babylonian priesthood of Marduk come into the history ancient apocalyptic dreaming as well). Certainly Jews and Zoroastrians had mutual respect for each other (witness King Cyrus being described as Messiah or God's Anointed in Isaiah, and the wise magoi = Zoroastrian priests coming to vist the Christ child according to Matthew's Gospel). Zoroastrianism's orginal impulse was monotheistic, even if it was less successful in the fulfilment of this, by comparison to Judaism (which after all experienced much internal strife over this issue!). Thus, out of this Near to Middle Eastern ambience, the millennial vision was born, and, eventually, unlike the use of one thousand (as in Exodus on a "thousand generations" = 40,000 years) to denote a long time in the future, a thousand becomes the typos of the enduring completion of God's eventual control of the known order (as in Revelation).