"Let the high praises of God be in their mouth, and a two-edged sword in their hand" (Ps. 149:6).
Psalm 149 represents Israel as triumphant over its enemies by the call and commission of God. In response to such a great victory, the nation of Israel praised God for executing His righteous judgment over the wicked and for keeping His promise to save the Israelites from the clutches of formidable foes.
The Israelites knew that their commission to exercise vengeance on these foreign kings came directly from God. They did not rail violently from a spirit of personal vengeance and hatred, but by a divinely appointed sword they executed God’s judgments upon others. God endowed Israel with a two-edged sword—a weapon that in the context of this psalm applies only to the Jews. God gave Israel the power and authority to destroy other nations in His name. He has not given any such power or authority to the church today. The magistrates and rulers certainly wield the sword as God has ordained, but the church does not brandish the sword in the name of religion. This duty ended with the kingdom of Israel. “As to the Church collective, the sword now put into our hand is of another kind, that of the word and spirit, that we may slay for a sacrifice to God those who formerly were enemies, or again deliver them over to everlasting destruction unless they repent,” Calvin wrote.
The double-edged sword of the church today is the Gospel of Christ. Christ does not intend that the Gospel should be propagated by violence, war, or politics, but it should be declared in peace. When we brandish this sword, we execute judgment on unbelievers by bringing them under conviction and conversion. Christ has crushed the strongholds of Satan, and in the last days final judgment will come by His hand. Because the church will reign with Christ, it too will judge the world (1 Cor. 6:2), thus fulfilling the words of the psalmist: “To execute on them the written judgment—this honor have all His saints” (v. 9). While the nation of Israel executed this judgment by the sword, the church today executes judgment through the Gospel. With our lips we proclaim the triumph of Christ over sin, and in our hands we carry the olive branch of peace. Let each of us praise God for His glorious victory in Christ as we worship Him in the congregation of saints.
God has called the church to certain duties—worship, service, proclamation of the Gospel, etc. Has He called the church to overcome its enemies by any other means? (2 Cor. 10). If you think so, can you find Scripture proof for your assertion? What weapons should the church employ to gain victory in this world (Eph. 6)?