7. Extent of Christianity in the Roman Empire. (Chapter 1: Spread of Christianity.) (History of the Christian Church) (Schaff, Philip)

Justin Martyr says, about the middle of the second century: There is no people, Greek or barbarian, or of any other race, by whatsoever appellation or manners they may be distinguished, however ignorant of arts or agriculture, whether they dwell in tents or wander about in covered wagons among whom prayers and thanksgivings are not offered in the name of the crucified Jesus to the Father and Creator of all things. Half a century later, Tertullian addresses the heathen defiantly: We are but of yesterday, and yet we already fill your cities, islands, camps, your palace, senate and forum; we have left to you only your temples. These, and similar passages of Irenaeus and Arnobius, are evidently rhetorical exaggerations. Origen is more cautious and moderate in his statements. But it may be fairly asserted, that about the end of the third century the name of Christ was known, revered, and persecuted in every province and every city of the empire. Maximian, in one of his edicts, says that almost all had abandoned the worship of their ancestors for the new sect.

In the absence of statistics, the number of the Christians must be purely a matter of conjecture. In all probability it amounted at the close of the third and the beginning of the fourth century to nearly one-tenth or one-twelfth of the subjects of Rome, that is to about ten millions of souls.

But the fact, that the Christians were a closely united body, fresh, vigorous, hopeful, and daily increasing, while the heathen were for the most part a loose aggregation, daily diminishing, made the true prospective strength of the church much greater.

The propagation of Christianity among the barbarians in the provinces of Asia and the north-west of Europe beyond the Roman empire, was at first, of course, too remote from the current of history to be of any great immediate importance. But it prepared the way for the civilization of those regions, and their subsequent position in the world.