Joel is a prophet who uses a devastating locust plague as a starting point to announce the great "Day of the Lord," a moment of divine judgment but also of restoration and hope. Through vivid and powerful imagery, the book calls the people to repent with all their heart and promises that God will pour out His Spirit on all flesh. It is a message that swings between urgent warning and one of the most comforting promises in the Bible.
The book of Joel is attributed to the prophet Joel, son of Pethuel, though no reigning king is mentioned, which makes it difficult to date precisely. Proposals range from the 9th century BC to the postexilic period in the 5th century BC, with the latter being the most widely accepted among many modern scholars. Joel is famous for the passage the apostle Peter quoted at Pentecost: "I will pour out my Spirit upon all flesh," turning this small book into a prophecy of enormous weight in the New Testament. With only 3 chapters, Joel is one of the shortest books of the Old Testament, yet its theological impact is extraordinarily profound.