The centurial plan, which prevailed from Flacius to Mosheim, is an improvement. It allows a much better view of the progress and connection of things. But it still imposes on the history a forced and mechanical arrangement; for the salient points or epochs very seldom coincide with the limits of our centuries. The rise of Constantine, for example, together with the union of church and state, dates from the year 311; that of the absolute papacy, in Hildebrand, from 1049; the Reformation from 1517; the peace of Westphalia took place in 1648; the landing of the Pilgrim Fathers of New England in 1620; the American emancipation in 1776; the French revolution in 1789; the revival of religious life in Germany began in 1817.
The true division must grow out of the actual course of the history itself, and present the different phases of its development or stages of its life. These we call periods or ages. The beginning of a new period is called an epoch, or a stopping and starting point.
In regard to the number and length of periods there is, indeed, no unanimity; the less, on account of the various denominational differences establishing different points of view, especially since the sixteenth century. The Reformation, for instance, has less importance for the Roman church than for the Protestant, and almost none for the Greek; and while the edict of Nantes forms a resting-place in the history of French Protestantism, and the treaty of Westphalia in that of German, neither of these events had as much to do with English Protestantism as the accession of Elizabeth, the rise of Cromwell, the restoration of the Stuarts, and the revolution of 1688.
But, in spite of all confusion and difficulty in regard to details, it is generally agreed to divide the history of Christianity into three principal parts -- ancient, mediaeval, and modern; though there is not a like agreement as to the dividing epochs, or points of departure and points of termination.
I. The history of Ancient Christianity, from the birth of Christ to Gregory the Great. a.d.1-590.
This is the age of the Graeco-Latin church, or of the Christian Fathers. Its field is the countries around the Mediterranean -- Western Asia, Northern Africa, and Southern Europe -- just the theatre of the old Roman empire and of classic heathendom. This age lays the foundation, in doctrine, government, and worship, for all the subsequent history. It is the common progenitor of all the various confessions.
The Life of Christ and the Apostolic Church are by far the most important sections, and require separate treatment. They form the divine-human groundwork of the church, and inspire, regulate, and correct all subsequent periods.
Then, at the beginning of the fourth century, the accession of Constantine, the first Christian emperor, marks a decisive turn; Christianity rising from a persecuted sect to the prevailing religion of the Graeco-Roman empire. In the history of doctrines, the first oecumenical council of Nicaea, falling in the midst of Constantine's reign, a.d.325, has the prominence of an epoch.
Here, then, are three periods within the first or patristic era, which we may severally designate as the period of the Apostles, the period of the Martyrs, and the period of the Christian Emperors and Patriarchs.
II. Medieval Christianity, from Gregory I to the Reformation. a.d.590-1517.
The middle age is variously reckoned -- from Constantine, 306 or 311; from the fall of the West Roman empire, 476; from Gregory the Great, 590; from Charlemagne, 800. But it is very generally regarded as closing at the beginning of the sixteenth century, and more precisely, at the outbreak of the Reformation in 1517. Gregory the Great seems to us to form the most proper ecclesiastical point of division. With him, the author of the Anglo-Saxon mission, the last of the church fathers, and the first of the proper popes, begins in earnest, and with decisive success, the conversion of the barbarian tribes, and, at the same time, the development of the absolute papacy, and the alienation of the eastern and western churches.
This suggests the distinctive character of the middle age: the transition of the church from Asia and Africa to Middle and Western Europe, from the Graeco-Roman nationality to that of the Germanic, Celtic, and Slavonic races, and from the culture of the ancient classic world to the modern civilization. The great work of the church then was the conversion and education of the heathen barbarians, who conquered and demolished the Roman empire, indeed, but were themselves conquered and transformed by its Christianity. This work was performed mainly by the Latin church, under a firm hierarchical constitution, culminating in the bishop of Rome. The Greek church though she made some conquests among the Slavic tribes of Eastern Europe, particularly in the Russian empire, since grown so important, was in turn sorely pressed and reduced by Mohammedanism in Asia and Africa, the very seat of primitive Christianity, and at last in Constantinople itself; and in doctrine, worship, and organization, she stopped at the position of the oecumenical councils and the patriarchal constitution of the fifth century.
In the middle age the development of the hierarchy occupies the foreground, so that it may be called the church of the Popes, as distinct from the ancient church of the Fathers, and the modern church of the Reformers.
In the growth and decay of the Roman hierarchy three popes stand out as representatives of as many epochs: Gregory I., or the Great (590), marks the rise of absolute papacy; Gregory VII., or Hildebrand (1049), its summit; and Boniface VIII. (1294), its decline. We thus have again three periods in mediaeval church history. We may briefly distinguish them as the Missionary, the Papal, and the pre- or ante-Reformatory  ages of Catholicism.
III. Modern Christianity, from the Reformation of the sixteenth century to the present time. a.d.1517-1880.
Modern history moves chiefly among the nations of Europe, and from the seventeenth century finds a vast new theatre in North America. Western Christendom now splits into two hostile parts -- one remaining on the old path, the other striking out a new one; while the eastern church withdraws still further from the stage of history, and presents a scene of almost undisturbed stagnation, except in modern Russia and Greece. Modern church history is the age of Protestantism in conflict with Romanism, of religious liberty and independence in conflict with the principle of authority and tutelage, of individual and personal Christianity against an objective and traditional church system.
Here again three different periods appear, which may be denoted briefly by the terms, Reformation, Revolution, and Revival.
The sixteenth century, next to the apostolic age the most fruitful and interesting period of church history, is the century of the evangelical renovation of the Church, and the papal counter-reform. It is the cradle of all Protestant denominations and sects, and of modern Romanism.
The seventeenth century is the period of scholastic orthodoxy, polemic confessionalism, and comparative stagnation. The reformatory motion ceases on the continent, but goes on in the mighty Puritanic struggle in England, and extends even into the primitive forests of the American colonies. The seventeenth century is the most fruitful in the church history of England, and gave rise to the various nonconformist or dissenting denominations which were transplanted to North America, and have out-grown some of the older historic churches. Then comes, in the eighteenth century, the Pietistic and Methodistic revival of practical religion in opposition to dead orthodoxy and stiff formalism. In the Roman church Jesuitism prevails but opposed by the half-evangelical Jansenism, and the quasiliberal Gallicanism.
In the second half of the eighteenth century begins the vast overturning of traditional ideas and institutions, leading to revolution in state, and infidelity in church, especially in Roman Catholic France and Protestant Germany. Deism in England, atheism in France, rationalism in Germany, represent the various degrees of the great modern apostasy from the orthodox creeds.
The nineteenth century presents, in part, the further development of these negative and destructive tendencies, but with it also the revival of Christian faith and church life, and the beginnings of a new creation by the everlasting gospel. The revival may be dated from the third centenary of the Reformation, in 1817.
In the same period North America, English and Protestant in its prevailing character, but presenting an asylum for all the nations, churches, and sects of the old world, with a peaceful separation of the temporal and the spiritual power, comes upon the stage like a young giant full of vigor and promise.
Thus we have, in all, nine periods of church history, as follows:
Christianity has thus passed through many stages of its earthly life, and yet has hardly reached the period of full manhood in Christ Jesus. During this long succession of centuries it has outlived the destruction of Jerusalem, the dissolution of the Roman empire, fierce persecutions from without, and heretical corruptions from within, the barbarian invasion, the confusion of the dark ages, the papal tyranny, the shock of infidelity, the ravages of revolution, the attacks of enemies and the errors of friends, the rise and fall of proud kingdoms, empires, and republics, philosophical systems, and social organizations without number. And, behold, it still lives, and lives in greater strength and wider extent than ever; controlling the progress of civilization, and the destinies of the world; marching over the ruins of human wisdom and folly, ever forward and onward; spreading silently its heavenly blessings from generation to generation, and from country to country, to the ends of the earth. It can never die; it will never see the decrepitude of old age; but, like its divine founder, it will live in the unfading freshness of self-renewing youth and the unbroken vigor of manhood to the end of time, and will outlive time itself. Single denominations and sects, human forms of doctrine, government, and worship, after having served their purpose, may disappear and go the way of all flesh; but the Church Universal of Christ, in her divine life and substance, is too strong for the gates of hell. She will only exchange her earthly garments for the festal dress of the Lamb's Bride, and rise from the state of humiliation to the state of exaltation and glory. Then at the coming of Christ she will reap the final harvest of history, and as the church triumphant in heaven celebrate and enjoy the eternal sabbath of holiness and peace. This will be the endless end of history, as it was foreshadowed already at the beginning of its course in the holy rest of God after the completion of his work of creation.
 This new word is coined after the analogy of ante-Nicene, and in imitation of the German vor-reformatorisch. It is the age of the forerunners of the Reformation, or reformers before the Reformation, as Ullmann calls such men as Wicklyffe, Huss, Savonarola, Wessel, etc. The term presents only one view of the period from Boniface VIII. to Luther. But this is the case with every other single term we may choose.