God Is Light

Having grounded his epistle in the historical reality of the incarnation and in the fellowship that flows from it, John now begins to set out the message that the Apostles proclaim. He summarizes this message in a single dense sentence: “God is light, and in him is no darkness at all” (1 John 1:5). Everything that follows in the rest of the letter unfolds from this affirmation about the divine nature.

The biblical use of light as an image for God draws on a rich Old Testament background. Light evokes truth, holiness, life, and revelation. Where God is, falsehood and unrighteousness cannot persist, just as physical darkness is dispelled by the rising of the sun. Psalm 27:1 calls the Lord “my light and my salvation.” Isaiah 60:19 promises that in the new creation, the Lord Himself will be Israel’s everlasting light. When John writes that God is light, he presses home these ideas: God is light, and there is no darkness in Him at all.

The denial that closes the verse is as important as the affirmation that opens it. There is no darkness in God whatsoever. God is not partly holy and partly sinful, partly truthful and partly deceptive, partly loving and partly cruel. He is unmixed in His goodness, perfect in His righteousness, and utterly trustworthy in His self-revelation. This is a truth that our fallen hearts struggle to receive. We are accustomed to see compromise even in those whom we most admire, and we project onto God the same mixture of light and darkness that we find in ourselves and others. John insists that the God revealed by the Apostles is altogether different. This affirmation also serves as the foundation for the moral instruction that follows in chapter 1. Because God is light, those who claim to have fellowship with Him must walk in the light themselves (1 John 1:6–7). The character of God establishes the standard for the conduct of His people. The false teachers troubling John’s congregation taught that the spiritual elite could indulge in immoral behavior without consequence. John flatly denies this. A claim to know God that is not accompanied by a life increasingly conformed to His holiness is no true claim at all.

This is why the doctrine of God matters so intensely for the Christian life. The truth about who God is shapes everything else about us, including our hopes, our fears, our loves, and the daily choices that we make.