When I was a boy, I was afraid of the dark. Who knew what bogeyman lurked in its shadows, or what under-the-bed monster went bump in the night? Not I. But I always knew the solution for my fears.
And what was the solution? God, obviously! Whenever I found myself trembling in bed with fear, I would pray to God or sing a hymn. (I admit I was a weird little kid.) Martin Luther’s A Mighty Fortress Is Our God was particularly effective in dispelling my fears, especially this lyric:
The Prince of Darkness grim, we tremble not for him;
His rage we can endure, for lo, his doom is sure,
One little word shall fell him.
There was (and still is) a great deal of comfort to be had from knowing that “the Prince of Darkness grim” is not strong enough to withstand “one little word” from God. As a boy facing monsters and bogeymen, and as a man worried about terrorists and suitcase nukes, such a truth helps keep my fears in perspective.
What is it about the dark that makes it so fearsome, or the light that makes it so welcome? For me, it is ignorance and knowledge, respectively. In the dark, we do not know because we cannot see; but in the light, we can both see and know. And that is why darkness and light are such spiritually suggestive metaphors. We do not know what evil the darkness hides, but in the light we see that goodness prevails.
Jesus evidently used the metaphors of darkness and light to describe our Heavenly Father. We do not find his usage of them in the Gospels, but 1 John 1:5 is quite clear that he used them nonetheless: “This is the message we have heard from him and declare to you: God is light; in him there is no darkness at all.”
Notice that Jesus engages in both positive and negative theology in this verse. Positively, “God is light.” Negatively, “in him there is no darkness at all.” These two statements amplify each other. God is not the first sliver of dawn, nor is darkness the gloaming. Rather, God is high noon in summer, and the darkness is pitch-black midnight on a cloudy, moonless night. They are the spiritual antitheses of one another.
According to I. Howard Marshall, light symbolizes both the “revelation and salvation” that God provides us, as well as the “holiness” he possesses and requires of us. Psalm 119:105 captures the intimate connection between revelation and salvation when it says, “Your word is a lamp to my feet and a light for my path.” God reveals so that he can save.
But it is holiness that is paramount in 1 John 1:5, as the verses that follow (and which we will study later) make clear. God has no secret sins. He is neither monster nor bogeyman. He is the absolute contradiction of those terrorists who do violence in his name.
Knowing this, whether young or old, we can sleep in peace.
 I. Howard Marshall, The Epistles of John (Grand Rapids, MI: Eerdmans, 1978), 109.