Millennium (Lat., 'a thousand years'), a long indefinite space during which the kingdom of the Messiah will, according to the belief of many Christians, be visibly established on the earth. The idea originated proximately in the Messianic expectations of the Jews; and the Christians' belief in the Parousia, or Second Coming of Christ, was developed by the oppression and persecutions to which they were long subjected. The chief basis of the millenarian idea, in Judaism as well as in Christianity, is the ardent hope for a visible divine rule upon earth, and the identification of the church with that of which it is merely a symbol. In the 1st century of the church, chiliasm (the Greek equivalent of millenarianism, from chilioi, 'a thousand') was a widespread belief, to which the books of Daniel and the Apocalypse (chaps. xx. and xxi.) gave authority; while various prophetic writings, composed at the end of the 1st and the beginning of the 2d century—such as the Testament of the Twelve Patriarchs, the Christian Sibylline Books, the Epistle of Barnabas—lent it a more vivid colouring and imagery. Not only the heretic Cerinthus, but even orthodox doctors—such as Papias of Hierapolis, Irenæus, and Justin Martyr—delighted themselves with dreams of the glory and magnificence of the millennial kingdom. The Sibylline Books, for instance, hold that the earth will be cultivated throughout its length and breadth, that there will be no more seas, no more winters, no more nights; everlasting wells will run honey, milk, and wine. Papias indulges in monstrous representations of the rebuilding of Jerusalem, and of the colossal vine and grapes of the millennial reign.
According to the general opinion, which was as much Christian as Jewish, the millennium was to be preceded by great calamities. The personification of evil appeared in Antichrist (q.v.), the precursor of Christ (identified during the 1st century with Nero), who would provoke a frightful war in the land of Magog (Ezek. xxxviii. and xxxix.) against the people Gog, after which the Messiah would appear, heralded by Elias, or Moses, or Melchizedek, or Isaiah, or Jeremiah, and would bind Satan for a thousand years, annihilate the godless heathen, or make them slaves of the believers, and overturn the Roman empire. From its ruins a new order of things would spring forth, in which the 'dead in Christ' would arise, and along with the surviving saints enjoy an incomparable felicity in the city of the 'New Jerusalem,' which was expected to descend literally from heaven. With the innocence which was the state of man in Paradise there was associated, in the prevalent notions of the millennium, great physical and intellectual pleasures.
The lapse of time, chilling the ardour of the primitive Christian belief in the nearness of the Parousia, had without doubt also the tendency to give a more shadowy, and therefore a more spiritual aspect to the kingdom over which the expected Messiah was to reign. The influence of the Alexandrian philosophy contributed to produce the same result. Origen, for example, started the idea that, instead of a final and desperate conflict between Paganism and Christianity, the real progress and victory of Christianity would consist in the gradual spread of the truth throughout the world, and in the voluntary homage paid to it by all secular powers. Yet even in the Egypto-Alexandrian Church millenarianism, in its most literal form, was widely diffused. The Montanists (q.v.) generally were extreme millenarians or chiliasts, and, being considered a heretical sect, contributed largely to bring chiliasm into discredit, or, at all events, their own carnal form of chiliasm, which Tertullian himself attacked. Lactantius, in the beginning of the 4th century, was the last important Church Father who indulged in chiliastic dreams. In the 5th century, St Jerome and St Augustine expressly combatted certain fanatics who still hoped for the advent of a millennial kingdom whose pleasures included those of the flesh. From this time the Church formally rejected millenarianism in its sensuous 'visible form,' although the doctrine every now and then made its reappearance, especially as a general popular belief, in the most sudden and obstinate manner. Thus, the expectation of the Last Day in the year 1000 A.D. reinvested the doctrine with a transitory importance.
At the period of the Reformation, millenarianism once more experienced a partial revival, because it was not a difficult matter to apply some of its symbolism to the papacy: the pope, for example, was Antichrist. Yet the doctrine was not adopted by the great body of the Reformers, but by some fanatical sects, such as the Anabaptists, as also by various theosophists in the next century. During the civil and religious wars in France and England it was also prominent; the Fifth Monarchy Men (q.v.) of Cromwell's time were millenarians of the most exaggerated type. The extravagances of the French Mystics and Quietists culminated in chiliastic views. During the Thirty Years' War enthusiastic and learned chiliasts flourished. Among the foremost chiliastic teachers of modern centuries are to be mentioned Ezechiel Meth and Bishop Comenius in Germany; Professor Jurien of Sedan, and Poiret; Serarius in Holland; and in England Joseph Mede (Clav. Apocal. 1627), while Thomas Burnet and William Whiston endeavoured to give chiliasm a geological foundation. Most of the chief divines of the Westminster Assembly were millenarians; so were Sir Isaac Newton and Bishop Horsley. Bengel revived an earnest interest in the subject among orthodox Protestants. Spener and Joachim Lange held chiliastic views; and Swedenborg employed apocalyptic images to set forth the transfigured world of the senses. Bengel's millenarianism was adopted by the Swabian theosophist Oettinger (died 1782), and widely spread throughout Germany by Jung Stilling, Lavater, and Hess. Charles Wesley and Toplady were millenarians.
Modern millenarians or pre-millennialists (as believing in the pre-millennial advent of Christ) differ in many minor points from one another, but agree in holding that the millennial age will be heralded by the personal return of the Lord Jesus, to establish a theocratic kingdom of universal righteousness, during which time sin will remain on earth but be greatly diminished. Immediately on Christ's appearing will take place the resurrection of the righteous dead and the translation of living Christians, who will be rewarded according to their works. The judgment work of Christ will occupy the whole millennial period. The Jews, restored to their own land, will repent and be converted. All the hosts of Antichrist will be destroyed, Satan bound, and the Holy Ghost poured out. At the end of the millennial age Satan released will make a last vain attempt to regain his power, but he and the wicked, who now have their resurrection, will be finally judged and cast into the lake of fire. The earth will be renewed by fire, and be the scene of the everlasting kingdom of Christ over all sanctified mankind. Attempts to fix the date of the advent are generally disapproved. Dates that have been fixed for the beginning of the millennium have been 1785 by Stilling, 1836 by Bengel, 1843 by Miller in America, 1866, 1867, and 1868 by Dr Cumming, and 1890 by the Mormon Church. Some adventists teach the doctrine of Apocatastasis (q.v.), others the final annihilation of the impenitent. See ADVENTISTS (SECOND), and HELL.
Many of the greatest modern German theologians have been more or less pronouncedly pre-millennialists; such as Rothe, Hofmann, Nitzsch, Ebrard, Lange, Delitzsch, Christlieb, Luthardt, as also Oosterzee, Gaussen, and Godet. The Free Church of Italy and the Plymouth Brethren collectively hold these views. The Irvingites expect the speedy appearance of Christ. Pre-millennial views appear in the works of many eminent Anglicans—such as Archbishop Trench, Bishops Ellicott and Ryle, Canons Fremantle and Hoare, Dean Alford. Amongst Presbyterians Dr John Cumming and Dr Horatius Bonar are conspicuous names. Great conferences of pre-millennialists were held in London and New York in 1878.
See Corrodi, Geschichte des Chiliasmus (1781; 2d ed. 1794); J. P. Lange, Das Land der Herrlichkeit (1838); Volck, Der Chiliasmus (1869); Bickersteth, Glory of the Church (1853); Bonar, Coming of the Kingdom of the Lord Jesus (1849), and Prophetic Landmarks (1859); Cumming, Apocalyptic Sketches (1849); E. B. Elliott, Howe Apocalyptic (5th ed. 1862); Seiss, The Last Times (7th ed. Phila. 1878); the Pre-millennial Essays of the Prophetic Conference (Chicago, 1879); and, against Millenarianism, David Brown, Christ's Second Coming (1846).