(from Notes on Eusebius’s Church History, 1890)
Chiliasm, or millennarianism,–that is, the belief in a visible reign of Christ on earth for a thousand years before the general judgment,–was very widespread in the early church. Jewish chiliasm was very common at about the beginning of the Christian era, and is represented in the voluminous apocalyptic literature of that day. Christian chiliasm was an outgrowth of the Jewish, but spiritualized it, and and fixed it upon the second, instead of the first, coming of Christ.
The chief Biblical support for this doctrine is Rev. 20: 1-6; and the fact that this book was appealed to so constantly by chiliasts in support of their views was the reason why Dionysius, Eusebius, and others were anxious to disprove its apostolic authorship. Chief among the chiliasts of the Ante-Nicene age were the author of the epistle of Barnabas, Papias, Justin Martyr, Irenaeus, and Tertullian; while the principle opponents of the doctrine were Caius, Origen, Dionysius of Alexandria, and Eusebius. After the time of Constantine, chiliasm was more and more widely regarded as a heresy, and received its worse blow from Augustine, who framed in its stead the doctrine, which from his time on was commonly accepted in the church, that the Millennium is the present reign of Christ, which began with His resurrection.
It is interesting to note, that although chiliasm had long lost its hold wherever the philosophical theology of the third century had made itself felt, it still continued to maintain its sway in other parts of the Church, especially in outlying districts in the East, which were largely isolated from the great centers of thought, and in the greater part of the West. By such Christians it was looked upon, in fact, as the very kernel of Christianity,–they lived as most Christians of the second century had, in the constant hope of a speedy return of Christ to reign in power upon the earth. The gradual exclusion of this remnant of early Christian belief involved the same kind of consequences as the disappearance of the belief in the continued possession by the church of the spirit of prophecy, and marks another step in the progress of the church from the peculiarly enthusiastic spirit of the first and second, to the more formal spirit of the third and following centuries.