The prophet's confession assumes a form which may strike us as somewhat singular. Why is it that he speaks of 'unclean lips,' rather than of an unclean heart? I suppose partly because, in a very deep sense, a man's words are more accurately a cast, as it were, from a man's character than even his actions, and partly because the immediate occasion of his confession was the words of the seraphim, and he could not but contrast what came burning from their pure lips with what had trickled from, and soiled, his own. But, however expressed, the consciousness of personal unlikeness to the holiness of God is the first result, and the instantaneous result, of any real apprehension of that holiness, and of any true vision of Him. Like some search-light flung from a ship over the darkling waters, revealing the dark doings of the enemy away out yonder in the night, the thought of God and His holiness streaming in upon a man's soul, if it does so in any adequate measure, is sure to disclose the heaving waters and the skulking foes that are busy in the dark. But it was not only the consciousness of sinfulness and antagonism that woke up instantaneously in response to that vision of the holy God. It was likewise a shrinking apprehension of personal evil from contact of God's light with Isaiah's darkness. 'Who shall ascend into the hill of the Lord? He that hath clean hands and a pure heart.' What is to become, then, of the man that has neither the one nor the other? The experience of all the world witnesses that whenever there comes, in reality, or in a man's conceptions or fancy, the contact of the supernatural, as it is called, with the natural, there is a shrinking, a sense of eerieness, an apprehension of vague possibilities of evil. The sleeping snake that is coiled in every soul stirs and begins to heave in its bulk, and wake, when the thought of a holy God comes into the heart. Now, I do not suppose that consciousness of sin is the whole explanation of that universal human feeling, but I am very sure it is an element in it, and I suspect that if there were no sin, there would be no shrinking.