He awed men by the fire when He made flame to burst from the pillar of cloud—a token at once of grace and fear: if you obey, there is the light; if you disobey, there is the fire; but since humanity is nobler than the pillar or the bush, after them the prophets uttered their voice,—the Lord Himself speaking in Isaiah, in Elias,—speaking Himself by the mouth of the prophets. But if thou dost not believe the prophets, but supposest both the men and the fire a myth, the Lord Himself shall speak to thee, “who, being in the form of God, thought it not robbery to be equal with God, but humbled Himself,” He, the merciful God, exerting Himself to save man. And now the Word Himself clearly speaks to thee, shaming thy unbelief; yea, I say, the Word of God became man, that thou mayest learn from man how man may become God.
Clement of Alexandria
Exhortation to the Heathen
Chapter I