Light is in all languages the symbol of knowledge, of joy, of purity. It is the source of life. Its very nature is to ray itself out into and conquer darkness. Its splendor dazzles every eye; all things rejoice in its beams. Darkness is the type of ignorance, of sorrow, of sin. But, whilst the symbol is thus rich in manifold revelations, probably purity and self-communication are the predominating ideas here.
John has been honoured to give the world the three great revelations that God is spirit, is light, is love. And this profound saying in some sense includes both the others, inasmuch as light, which to the popular mind is most widely apart from matter, may well stand for the emblem of spirit, and, since to radiate is its inseparable quality, does represent in symbol the delight in imparting Himself, which is the very heart of the declaration that God is love. If, then, we grasp these two thoughts of absolute purity and of self-impartation as the very nature and property of God, John tells us that we grasp the kernel of the Gospel.
And he thinks that men never will grasp them certainly unless a message' from God, a definite revelation in historical fact, certifies them. We may hope or doubt, or desire, but we cannot be sure that God is light unless he tells us so by unmistakable act. John knew what act that was--the sending of His only-begotten Son. To the positive statement John, in his usual manner, appends an emphatic negative one: Darkness is not in him, no, not in any way.' He is light, all light, only light.
