“The Assyrians will be terror-stricken at the voice of the Lord, when he strikes with his rod. And every stroke of the appointed staff that the Lord lays on them will be to the sound of tambourines and lyres. Battling with brandished arm, he will fight with them.” (Isaiah 30:31-32)
God promised to strike Assyria “with his rod” (v.31). If that’s a film, then the soundtrack is worship – He will strike Assyria “to the sound of tambourines and lyres” (v.32). This is the order of conquest. This is the pattern by which the kingdom of God envelopes the earth and brings all things in subjection to Christ. God fights the battle; God’s people raise the battle cry. God wins; God’s people worship.
This is the prominent battle strategy in the Old Testament. Israel is constantly told to take cities and countries which they have no power to take. Israel is repeatedly commanded to accomplish the impossible. When they asked, “How might we do this impossible thing?” God responded, “I will give it to You.” In the Old Covenant, the church was to march forward in faith and worship. The New Covenant church is no different – which is what the book of Revelation demonstrates. God conquers amidst the praises of His people.
God will slay evil; our task is to worship and obey Him while He does it. Acting otherwise is to offer what Solomon calls a sacrifice of fools (Ecclesiastes 5). So go love your children, wash your dog, change your oil, and worship God in your local church, and do it all with joy. God is slaying the Assyrians to the tune of your obedience.