MILLENNIUM, literally a period of a thousand years, (a pseudo-Latin word formed on the analogy of biennium, triennium, from Lat. mille, a thousand, and annus, year). The term is spe cially used of the period of ',coo years during which Christ, as has been believed, would return to govern the earth in person. Hence it is used to describe a vague time in the future when all flaws in human existence will have vanished, and perfect good ness and happiness will prevail.
Faith in the nearness of Christ's second advent and the estab lishing of his reign of glory on the earth was undoubtedly a strong point in the primitive Christian Church. In the anticipa tions of the future prevalent amongst the early Christians (c. 50 150) it is necessary to distinguish a fixed and a fluctuating ele ment. The former includes (I) the notion that a last terrible battle with the enemies of God was impending; (2) the faith in the speedy return of Christ; (3) the conviction that Christ will judge all men, and (4) will set up a kingdom of glory on earth. To the latter belong views of the Antichrist, of the heathen world power, of the place, extent, and duration of the earthly kingdom of Christ, etc. These remained in a state of solution ; they were modified from day to day, partly because of the changing circum stances of the present by which forecasts of the future were regulated, partly because the indications—real or supposed—of the ancient prophets always admitted of new combinations and constructions. But even here certain positions were agreed on in large sections of Christendom. Amongst these was the ex pectation that the future kingdom of Christ on earth should have a fixed duration—according to the most prevalent opinion, a duration of i,000 years. From this fact the whole ancient Christian eschatology was known in later times as "chiliasm"— a name which is not strictly accurate, since the doctrine of the millennium was only one feature in its scheme of the future.
This idea that the Messianic kingdom of the future on earth should have a definite duration has—like the whole eschatology of the primitive Church—its roots in the Jewish apocalyptic literature, where it appears at a comparatively late period. At first it was assumed that the Messianic kingdom in Palestine would last for ever (so the prophets; cf. Jer. xxiv. 6; Ezek. xxxvii. 25; Joel iv. zo; Dan. vi. 27; Sibyll. iii. 49 seq., 766; Psalt. Salom. xvii. 4 Enoch lxii. 14), and this seems always to have been the most widely accepted view (John xii. 34). But from a comparison of prophetic passages of the Old Testament learned apocalyptic writers came to the conclusion that a dis tinction must be drawn between the earthly appearance of the Messiah and the appearance of God Himself amongst His people and in the Gentile world for the final judgment.
Nowhere in the discourses of Jesus is there a hint of a limited duration of the Messianic kingdom. The apostolic epistles are equally free from any trace of chiliasm (neither i Cor., xv. 23 seq. nor i Thess., iv. i6 seq. points in this direction). In Revelation however, it occurs in the following shape (ch. xx.). After Christ has appeared from heaven in the guise of a warrior, and van quished the anti-Christian world-power, the wisdom of the world and the devil, those who have remained steadfast in the time of the last catastrophe, and have given up their lives for their faith, shall be raised up, and shall reign with Christ on this earth as a royal priesthood for i,000 years. At the end of this time Satan is to be let loose again for a short season; he will prepare a new onslaught, but God will miraculously destroy him and his hosts. Then will follow the general resurrection of the dead, the last judgment, and the creation of new heavens and a new earth. That all believers will have a share in the first resur rection and in the Messianic kingdom is an idea of which the author of Revelation knows nothing. The earthly kingdom of Christ is reserved for those who have endured the most terrible tribulation, who have withstood the supreme effort of the world power—that is, for those who are actually members of the church of the last days. The Jewish expectation is thus considerably curtailed, as it is also shorn of its sensual attractions. "Blessed and holy is he that bath part in the first resurrection ; on such the second death hath no power ; but they shall be priests of God and of Christ, and shall reign with Him a thousand years." Other ancient Christian authors were not so cautious. Accepting the Jewish apocalypses as sacred books of venerable antiquity, they read them eagerly, and transferred their contents bodily to Chris tianity. Nay more, the Gentile Christians took possession of them, and just in proportion as they were neglected by the Jews —who, after the war of Bar-Cochba, became indifferent to the Messianic hope and hardened themselves once more in devotion to the law—they were naturalized in the Christian communities. The result was that these books became "Christian" documents; it is entirely to Christian, not to Jewish, tradition that we owe their preservation. The Jewish expectations are adopted for example, by Papias, by the writer of the epistle of Barnabas, and also by Justin. That a philosopher like Justin, with a bias towards an Hellenic construction of the Christian religion, should nevertheless have accepted its chiliastic elements is the strongest proof that these enthusiastic expectations were inseparably bound up with the Christian faith down to the middle of the 2nd century.