God's Army appears in prophecy as the instrument of divine wrath on the Day of the Lord. The Feast of Trumpets, observed with the blowing of the shofar, serves as an annual memorial and warning of that approaching day, when a great and strong people unlike any other will advance in perfect formation. Their advance devours the land like fire, darkens the sun and moon, and leaves desolation behind them. The prophet Joel identifies this force explicitly as the LORD's own army and camp, led by the LORD Himself, who gives voice before it. The army's actions consist of killing and breaking in perfect righteousness, for the LORD executes His word through it. This judgment arises because sin has accumulated like water behind a dam, and the LORD, being just, must release the flood of vengeance when the time comes. The same Being who led Israel out of Egypt, gave the law at Sinai, and scattered the bodies of the disobedient in the wilderness is the One who will head this army at His return. Thus the topic of God's Army develops directly from the meaning of the Feast of Trumpets into a larger revelation of divine character: the LORD is both gracious and a consuming fire, forming light and creating darkness, making peace and creating calamity. Those who refuse to heed the warning face the army's advance; those who repent and put on faith, love, and the hope of salvation are appointed instead to obtain salvation through the returning King.