When reporters on television speak about a criminal’s record, they may say his record indicates a high rate of “recidivism.” Most TV viewers probably would not understand what the reporter said. Similarly, when theologians speak about the “efficacy” of God’s Word, probably 90% or more of the people in the LCMS would not know what “efficacy” means.


Since I spend much of my time as an evangelist trying to write and speak clearly in a way that the man on the street can understand, I use the word “efficacy” as sparingly as possible. To be honest, I try to avoid it completely. Nevertheless, no matter how we may feel about using “efficacy” to describe God’s Word, we are pretty well stuck with the definition Lutheran theologians use.


For a somewhat simplified definition of the “efficacy” of God’s Word, Luther writes: “What appears to be more meaningless than a word? And yet when God speaks a word, the thing expressed by the word immediately leaps into existence. God says to my mother: ‘Conceive!’ and she conceives. He says to me: ‘Be born!’ and I am born” (LW 13:99). In other words, God could say: “Eiffel Tower!” and a full Eiffel Tower would instantly appear. God could say: “Grand Canyon!” and a second Grand Canyon would instantly appear. This is why Luther, whose writings are saturated with the teaching of the “efficacy” of God’s Word, repeatedly quotes Psalm 33:9, “He spoke, and it was done; He commanded, and it stood fast.” Luther also frequently quoted Romans 4:17, “God . . . calls into being that which does not exist.”


In order to show God’s Word is efficacious as compared to man’s non-efficacious word, St. Paul writes in 1 Thessalonians 2:13, “And for this reason we also constantly thank God that when you received from us the word of God's message, you accepted it not as the word of men, but for what it really is, the word of God, which also performs its work in you who believe.” The most consoling and encouraging words in this entire discussion are those from Jesus when he says in John 5:17, “My Father is working until now, and I Myself am working.” When Jesus says this, He is, of course, referring to His Word. Jesus also says in John 6:63, “The words that I have spoken to you are spirit and are life.”


For those of you who desire additional Bible passages on the efficacy of God’s Word, here are only a few of the many, many verses God has given us in His Scriptures where He Himself speaks about the efficacy of His living Word: Deuteronomy 8:3; Psalm 33:6; 107:20; 119:28, 50, 93, 107, 116, 149, 154, 156; Proverbs 4:20–22; Isaiah 55:11; Jeremiah 1:12; Lamentations 2:17; Ezekiel 12:25–28; 37:7; John 4:41; 5:25; 6:68; Acts 12:24; 19:20; Romans 9:28; 10:17; 1 Corinthians 1:21; Hebrews 4:12; James 1:21; 1 Peter 1:23; 2:2.


Click here to return to the main part of the essay.