The author of Hebrews says, “The word of God is living and active, sharper than any two edged sword,” (Hebrews 4:12). A sharp sword is a powerful and dangerous weapon. It’s something that must be handled with care, lest it do great harm. But in our battle against the rulers, authorities, and cosmic powers over this present darkness (Ephesians 6:12), nothing less powerful is needed. God’s Word is our chief weapon in this war. It is of the utmost importance that this sword remain sharp, living, and active in our lives.
Again and again the Bible teaches about the two edges of God’s sword, that it both kills and makes alive. The prophet Jeremiah describes God’s Law as a hammer that smashes the rock into pieces (Jeremiah 23:28). God’s Law puts an end to pride and all sinful desires. Those who heard the apostle’s preaching on the Day of Pentecost were “cut to the heart” when they heard God’s Law, how their sin put Jesus to death (Acts 2:36).
But God’s Word has two edges. It kills, but it doesn’t leave you dead. When the crowd asked, “What shall we do?”, St. Peter’s response was, “Repent and be baptized, every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit,” (Acts 2:38). In other words, do nothing. Let God do all of the work. Let Him baptize every one of us, from infant to adult, for the forgiveness of sins and the gift of the Holy Spirit. God’s Word brings dead sinners to life.
Just as God’s Word has two edges, so also there are two ways it can become dulled in our lives. Both pertain to our proclamation of God’s Word: the first in word, the second in deed. Take care, lest this sword become dull in your life! Both are equally as dangerous.
Since God’s Word is the chief weapon against Satan, nothing pleases him more than when our proclamation of God’s Word becomes dull. This happens especially when we don’t preach the Gospel in all its truth and purity. Where our understanding of Scripture is lacking, our proclamation will be weak. God’s Word is also dulled when we understand what it teaches, but for one reason or another, we fail to speak up and correct error. God’s Word is a sharp sword. It’s not always pleasant to wield. Surgery often involves cutting people open, but it may be the only way to bring healing. When we withhold the truth of God’s Word from someone, we fail to love them, even when we’re trying to spare them the difficult truth.
We need a weapon like God’s Word against the devil because he is a murderer and delights in violence (John 8:44). The history of Christianity bears out how many have died for confessing the Word of God in its truth and purity: countless prophets, apostles, and martyrs, chief among whom is our Lord Jesus Christ. Satan hasn’t had as much success in our country with the physical persecution of Christians, though a pure confession of Christ these days may be considered politically incorrect at best, and hate speech at worst. It should not surprise us then, that in a country where Satan has difficulty attacking Christians physically, he’s put a tremendous amount of effort into attacking the purity of God’s Word. It’s not that pure doctrine is required to get into heaven. But false doctrine is dangerous, even deadly, much as a person can have heart disease or a brain tumor and still be alive. To not seek an immediate cure for such a malady would be foolish. It becomes very difficult to ward off Satan where the truth of God’s Word has become dulled.
Examples of how God’s Word has become dulled today could be multiplied. False teaching on human sexuality and marriage; legalism and antinomianism; open communion; denying the real presence of Christ in Word and Sacrament; decision theology; and refusal to reject all false paths to salvation are commonplace in our day, just to name a few. Where these things (and any other perversions of God’s Word) are taught, God’s Word is dulled in our lives.
The Word is sharpened by Christian catechesis. Remain a lifelong disciple of the Word. Don’t study it in isolation. Christians have always learned in community, at the feet of orthodox teachers and with other Christians who share a pure confession of Christ (Titus 1:9; Romans 16:17). Make use of good materials in personal Bible study, things that will help you confess the Scriptures clearly and purely. Chief among these would be the Small Catechism, along with all of the other writings in the Book of Concord.
However, God’s Word can be dulled in another way, even where our confession of the Gospel remains pure, verbally speaking. God’s Word is dulled in our lives when we fail to live according to His will. This is why St. James writes, “Be doers of the word, and not hearers only, deceiving yourselves,” (James 1:22). Scandalous, hypocritical living will dull your ability to speak the truth of the Gospel. Nobody will listen to what you have to say about Jesus, no matter how true your words may be, if your life contradicts your faith. St. Paul calls all Christians to walk in a manner worthy of the Gospel (Ephesians 4:1). Where wicked living abounds, God’s Word is dulled in our lives.
Worse, there’s nothing we can do to sharpen this sword once it has become dull. There’s no way for us to buff out the corrosion of sin in our lives. Only God can repair the damage we’ve done. Our only hope is the grace of God. His Word creates something new and better. His washing of rebirth and renewal take away our sin and replace it with His righteousness (Titus 3:5—7). His Body and Blood empower a life of faith in Him and fervent love for one another. His grace alone keeps this Sword sharp in our lives, enabling us to proclaim the Gospel purely in both Word and deed.
Jesus taught about the importance of prayer in keeping this sword from becoming dull. He instructs us to pray, as we do in The First Petition: “Hallowed be Thy Name.” In this petition we ask that our dear Father in heaven would help us to keep His Word holy in our teaching and in our lives. We are to pray to the Father in Jesus’ name (John 16:24), which is essential if we are to “think those things that are right and by [His] merciful guidance accomplish them,” (Collect for the Sixth Sunday of Easter). Without prayer, God’s Word can only become dull in our lives.
So we pray for faith. Where faith becomes dull, sinful actions follow. And faith that fails to bear fruit is a dead tree. Every sin is an act of unbelief. It is to reject the claim of God on your life in favor of something else. This is why, when explaining each of The Ten Commandments, Luther began with the words, “We should fear and love God.” Where fear and love of God, or faith, is lacking, sin can only follow.
The two edges of God’s Word remained sharp in Jesus’ life, and it cost Him His life. His pure testimony of the Word was deemed blasphemy (Matthew 26:63—68). His actions, especially his association with those who led openly sinful lives, offended those who thought God’s favor was only for people who had earned it (Luke 15:1—2). Painful as it is to hear, the prophet Isaiah declares our very best works to be repulsive in God’s eyes (Isaiah 64:6).
Only One Person has ever earned the favor of God. Only One has ever kept the Word of God sharp in both word and deed. That was none other than the Word made Flesh, our Lord Jesus Christ. But the sword didn’t spare Him. He spoke the truth, and we killed Him for it. This sword of God’s wrath executed the Innocent One, that the guilty might be set free (2 Corinthians 5:21). So also this sword pierces His mother and all of His disciples, even down to this day (Luke 2:35; John 15:18; Matthew 10:25).
God’s Word is living and active, a sharp two-edged sword. Let this Word inform your every word and deed. Remain steadfast in prayer. Take up the whole armor of God (Ephesians 6:10—19). Make liberal use of the Absolution’s healing balm. Nourish your weary bodies on the Bread and Wine of Life. This is how, by His grace, He keeps the two-edged sword of His Word living and active in our lives, in both word and deed. May God grant this to us all.
 See further Kolb and Arand, The Genius of Luther’s Theology. Grand Rapids: Baker Academic, 209.