Mission and Expansion of Christianity in the First Three Centuries

Dr Harnack opened the course of lectures which have been translated in this library under the title What is Christianity? with a reference to John Stuart Mill. The present work might also be introduced by a sentence from the same English thinker. In the second chapter of his essay upon "Liberty," he has occasion to speak with admiration and regret of the Emperor Marcus Aurelius, confessing that his persecution of the Christians seems "one of the most tragical facts in all history." "It is a bitter thought," he adds, "how different a thing the Christianity of the world might have been, if the Christian faith had been adopted as the religion of the empire under the auspices of Marcus Aurelius instead of those of Constantine." Aurelius represents the apex of paganism during the first three centuries of our era. Chronologically, too, he stands almost equidistant between Christ and Constantine. But there were reasons why the adjustment of the empire to Christianity could not come earlier than the first quarter of the fourth century, and it is Dr Harnack's task in the present work to outline these reasons in so far as they are connected with the extension and expansion of Christianity itself.