'If we walk in the light, as He is in the light, we have fellowship one with another, and the blood of Jesus Christ His Son cleanseth us from all sin.'--1 John i. 7.
John was the Apostle of love, but he was also a 'son of thunder.' His intense moral earnestness and his very love made him hate evil, and sternly condemn it; and his words flash and roll as no other words in Scripture, except the words of the Lord of love. In the immediate context he has been laying down what is to him the very heart of his message, that 'God is light, and in Him is no darkness at all.' There are spots in the sun, great tracts of blackness on its radiant disc; but in God is unmingled, perfect purity. That being so, it is clear that no man can be in sympathy or hold communion with Him, unless he, too, in his measure, is light.
So, with fiery indignation, John turns to the people, of whom there were some, even in the primitive Church, who made claims to a lofty spirituality and communion with God, and all the while were manifestly living in the darkness of sin. He will not mince matters with them. He roundly says that they are lying, and the worst sort of lie--an acted lie: 'They do not the truth.' Then, with a quick turn, he opposes to these pretenders the men who really are in fellowship with God, and in my text lays down the principle that walking in the light is essential to fellowship with God. Only, in his usual fashion, he turns the antithesis into a somewhat different form, so as to suggest another aspect of the truth, and instead of saying, as we might expect for the verbal accuracy of the contrast, 'If we walk in the light, as He is in the light, we have fellowship with God,' he says, 'we have fellowship one with another.' Then he adds a still further result of that walk, 'the blood of Jesus cleanses from all sin.'
Now there are three things: walking in the light, which is the only Christian walk; the companions of those who walk in the light; and the progressive cleansing which is given.
I. Note this 'Walking in the light,' which is the only Christian walk.
In all languages, light is the natural symbol for three things: knowledge, joy, purity. The one ray is broken into its three constituent parts. But just as there are some surfaces which are sensitive to the violet rays, say, of the spectrum, and not to the others, so John's intense moral earnestness makes him mainly sensitive to the symbolism which makes light the expression, not so much of knowledge or of joy, as of moral purity. And although that is not exclusively his use of the emblem, it is predominately so, and it is so here. To 'walk in the light' then, is, speaking generally, to have purity, righteousness, goodness, as the very element and atmosphere in which our progressive and changeful life is carried on.
Note, too, before I go further, that very significant antithesis: we 'walk'; He _is_--God _is_ in the light essentially, changelessly, undisturbedly, eternally; and the light in which He is, His 'own calm home, His habitation from eternity,' is light which has flowed out from Himself as a halo round the midnight moon. It is all one in substance to say God is in light, or, as the Psalmist has it, 'He covered Himself with light as with a garment,' and to say, 'God is light.'
But, side by side with that changeless abiding in the perfect purity, which is inaccessible, the Apostle ventures to put, not in contrast only, but in parallel (_as_ He is), our changing, effortful, active, progressive life in the light (God is); we walk.
So, then, the essential of a Christian character is that the light of purity and moral goodness shall be as the very orb, in the midst of which it stands and advances. That implies effort, and it implies activity, and it implies progress. And we are only Christians in the measure in which the conscious activities of our daily lives, and the deepest energies of our inward being, are bathed and saturated with this love of, and effort after, righteousness. It is vain, says John, to talk about fellowship with God, unless the fellowship is rooted in sympathy with Him in that which is the very heart of his Being, the perfect light of perfect holiness. Test your Christianity by that.