The subject might be further pursued, but enough has been said to furnish a key to the origin of the Gospels. Christians in their contests with the Pagans resemble the course of a retreating army, which falls back to take a stronger position. Each time the position is improved, until one at last is found which is impregnable. We can readily see how it is that the first three Gospels so closely resemble each other, the exact language for whole passages being alike in all. Mark copies Matthew, and Luke uses the words of both. It is only when the last undertakes to improve or modify something written by those who wrote previously, that the difference becomes obvious. That the Christians in the beginning of the second century had books of some kind before the three first Gospels appeared in the present shape is beyond all dispute. The sacred writings of the Therapeutæ, as we have shown, were full of the most sound morality, and contained all the essential principles of Christianity. These writings were ancient--had been regarded as sacred for generations among them, and were so much like the present Gospels that Eusebius claimed them to be the same, and that the Therapeutæ were Christians. No doubt the Hebrew Gospel of Matthew was extant, and if it was rejected by the Christians of that day, because it did not contain the two first chapters of the Greek version, there was no reason why they should reject the Sermon on the Mount, and all the sublime and pure religion taught by Christ. The sacred writings of the Therapeutæ--the Hebrew version of Matthew, the Epistle of James and the first of Peter--furnished the principles and doctrines which now form the life of Christianity; and the great want of the day--that is, some proof of the actual existence of the person of Christ, by those who had seen him and were familiar with him before his death--was supplied in the first three Gospels, by the testimony of those who claimed to be his disciples, or by those who, it is said, wrote at their dictation.