The Theological Dictionary: God’s Two Words—Law and Gospel
God acts by speaking.
“The word of God is living and active” (Heb. 4:12). This is the starting point for law/gospel theology. God acts by speaking. He says, “Let there be light” and the sun shines. He says, “Lazarus, come out” and “Little girl, get up” and the dead are raised. God’s words are actions, they do what they say. And what God does with words is condemn and forgive (Rom. 3.19-24; 11:32), kill and make alive (1 Sam. 2:6). The theological name for God’s condemning and killing speech is law. The theological name for God’s forgiving and life-giving speech is gospel. Both words are good; both words are God’s word. But they are distinct; they have different jobs. By encountering sinners with his holy demands—by telling sinners what they must do—God reveals that he is God and they are not, simultaneously exposing sin and condemning the sinner. By encountering sinners with his gracious promise—by telling sinners what Jesus has done, is doing, and will do—God forgives sin and creates new life. God’s word is “divided” by this double-action, by these “two-words” (Jer. 33:14): God accuses and kills sinners by speaking law; God acquits and resurrects them by speaking gospel.