I. First, just a word about the great conception of a Christian man's office which is set forth in that metaphor, 'Ye are the light of the world.'
That expression is wide, 'generic,' as they say. Then in the unfolding of this little parable our Lord goes on to explain what kind of a light it is to which He would compare His people--the light of a lamp kindled. Now that is the first point that I wish to deal with. Christian men individually, and the Christian Church as a whole, shine by derived light. There is but One who is light in Himself. He who said, 'I am the light of the world, he that followeth Me shall not walk in darkness,' was comparing Himself to the sunshine, whereas when He said to us, 'Ye are the light of the world; men do not light a lamp and put it under a bushel,' He was comparing us to the kindled light of the lamp, which had a beginning and will have an end.
Before, and independent of, His historical manifestation in the flesh, the Eternal Word of God, who from the beginning was the Life, was also the light of men; and all the light of reason and of conscience, all which guides and illumines, comes from that one source, the Everlasting Word, by whom all things came to be and consist. 'He was the true light which lighteth every man that cometh into the world.' And further, the historic Christ, the Incarnate Word, is the source for men of all true revelation of God and themselves, and of the relations between them; the Incarnate Ideal of humanity, the Perfect Pattern of conduct, who alone sheds beams of certainty on the darkness of life, who has left a long trail of light as He has passed into the dim regions beyond the grave. In both these senses He is the light, and we gather our radiance from Him.
We shall be 'light' if we are 'in the Lord.' It is by union with Jesus Christ that we partake of His illumination. A sunbeam has no more power to shine if it be severed from the sun than a man has to give light in this dark world if He be parted from Jesus Christ. Cut the current and the electric light dies; slacken the engine and the electric arc becomes dim, quicken it and it burns bright. So the condition of my being light is my keeping unbroken my communication with Jesus Christ; and every variation in the extent to which I receive into my heart the influx of His power and of His love is correctly measured and represented by the greater or the lesser brilliancy of the light with which I reflect His radiance. Ye were some time darkness, but now are ye light in the Lord.' Keep near to Him, and a firm hold of His hand, and then you will be light.
And now I need not dwell for more than a moment or two upon what I have already said is included in this conception of the Christian man as being light. There are two sides to it: one is that all Christian people who have learned to know Jesus Christ and have been truly taught of Him, do possess a certitude and clearness of knowledge which make them the lights of the world. We advance no claims to any illumination as to other than moral or religious truth. We leave all the other fields uncontested. We bow humbly with confessed ignorance and with unfeigned gratitude and admiration before those who have laboured in them, as before our teachers, but if we are true to our Master, and true to the position in which He has placed us, we shall not be ashamed to say that we believe ourselves to know the truth, in so far as men can ever know it, about the all-important subject of God and man, and the bond between them.