They all set forth Christianity as a revelation from God, given in the Old Testament through the inspired prophets, who had foretold the supreme revelation in Jesus Christ. Christianity therefore was something which had existed from the beginning of the world; it was a thing which revelation had continuously attested, and which consequently was ultimate truth.[337] According to Justin not only the prophets of the Old Testament but also the Greek philosophers had borne witness to the truth and had been in a measure Christians. This power of insight and of prophecy he would ascribe in the latter case as in the former to the operation of the reason of God, a seed of which was granted to every man by nature; all therefore that was reasonable in Greek thought was due to divine inspiration. He found the cause of the Greeks’ failure to expound the whole truth in the view that man’s natural endowment was insufficient to enable him to resist the evil demons which beset him.[338] Although Athenagoras did not say that every man had within him a germ of the divine wisdom, he no less than Justin granted that the pagan poets and philosophers had known the truth in part;[339] their errors had been due to their dependence on themselves. The full truth then was to be found in revelation, which gave the Apologists the sole and sufficient warrant of their faith and the complete rule of life. But, as I have said, the Apologists represented Christianity as the one valid philosophy. We must now examine briefly its principles. First as to the nature of God. In dealing with this subject the Apologists used a method of thought and of expression very much like that employed by Philo and the later Platonists. They contrasted God and the world: the latter they said was created, temporal, and conditioned; the former, unconditioned, eternal, and self-existent; the material world was apprehended by the senses, God by the mind and reason alone.[340] God, therefore, to them was the One, pure spirit, unchanging, requiring nothing. It followed from this idea of God that he must be regarded as supramundane, if not transcendent. As a matter of fact, these writers were perhaps unconsciously trying to reconcile the personal attributes of God the Father, which the common Christian faith ascribed to the Godhead, and the current concept of God as a transcendent and ineffable being. A variety of expressions, too numerous to be quoted here, was employed to suggest God’s exalted and perfect nature. Furthermore God was not regarded as a passive, but as a living and active spirit, who must express himself in creations; he was therefore the First Cause, the Lord, Father, and Creator of all. The perfection of his nature made him also the source of moral good.