Rend your heart and not your garments;
Return to the Lord your God, for he is gracious and merciful,
slow to anger and rich in abiding love.
Joel, which means “Yahweh is God” in Hebrew, is the second book of the Minor Prophets, and is believed to have been written after the exile in Babylon, around 400 B.C. Some think it was one of the last prophetic books to be completed, since many of its verses refer to earlier books in the Old Testament. But it is unique in its emphasis on lamentation and repentance, and in its apocalyptic style.
The first two chapters of the book are a ceremony asking God for forgiveness. The prophet calls the priests of God to “summon everybody to the Temple” to weep, fast, and mourn for their sins and to beg God to spare them his wrath. Already a plague of locusts has been through followed by nasty desert winds. The Israelites eventually evoke God’s compassion— God promises to make up for all that locust business by creating a land of abundance and never letting his “people be humiliated again.”
In the last two chapters of the book, Joel describes a battle where God destroys Israel’s enemies and allows Israel to prosper (see warfare in the Old Testament). This is where things start going apocalyptic style— the sun turning dark, the moon turning to blood, and the earth trembling, the destruction of the present world and the creation of a new one. A faithful remnant will survive, for whom Yahweh will be a “shelter” and a “stronghold.”