I know, of course, that, apart altogether from the exercise of faith in Jesus Christ, there do shine in men's hearts rays of the light of knowledge and of purity; but if we believe the teaching of Scripture, these, too, are from Christ, in His universally-diffused work, by which, apart altogether from individual faith, or from a knowledge of revelation, He is 'the light that lighteth every man coming into the world.' And I hold that, wheresoever there is conscience, wheresoever there is judgment and reason, wheresoever there are sensitive desires after excellence and nobleness, _there_ is a flickering of a light which I believe to be from Christ Himself. But that light, as widely diffused as humanity, fights with, and is immersed in, darkness. In the physical world, light and darkness are mutually exclusive: where the one is the other comes not; but in the spiritual world the paradox is true that the two co-exist. Apart from revelation and the acceptance of Jesus Christ's person and work by our humble faith, the light struggles with the darkness, and the darkness obstinately refuses to admit its entrance, and 'comprehendeth it not.' And so, ineffectual but to make restless and to urge to vain efforts and to lay up material for righteous judgment, is the light that shines in men whose hearts are shut against Christ. The fruitful light is Christ within us, and, unless we know and possess it by the opening of heart and mind and will, the solemn words preceding my text are true of us: 'Ye were sometime darkness.' Oh, brother! do you see to it that the subsequent words are true of you: 'Now are ye light in the Lord.' Only if you are in Christ are you truly light. II. Now, secondly, notice the fruitfulness of this indwelling light. Of course the metaphor that light, like a tree, grows and blossoms and puts forth fruit, is a very strong one. And its very violence and incongruity help its force. Fruit is generally used in Scripture in a good sense. It conveys the notion of something which is the natural outcome of a vital power, and so, when we talk about the light being fruitful, we are setting, in a striking image, the great Christian thought that, if you want to get right conduct, you must have renewed character; and that if you have renewed character you will get right conduct. This is the principle of my text. The light has in it a productive power; and the true way to adorn a life with all things beautiful, solemn, lovely, is to open the heart to the entrance of Jesus Christ.