The book of Joel, explained simply

Who wrote it

The book names its author as Joel son of Pethuel. Nothing else is known about him beyond what this book shows: he spoke for God to the people of Judah and Jerusalem and knew the life of the temple, Jerusalem's central place of worship, well.

When

Nobody knows for sure. The book names no king and no datable event, so suggestions range across several centuries, from before 700 BC to around 400 BC. Many modern scholars lean toward the later end, after the Jewish people returned from exile in Babylon, because the temple is standing, priests and elders lead the people, no king is mentioned, and the Greeks appear as slave traders. Whatever the date, the setting is Judah facing a crushing locust swarm and drought that wiped out crops, vines and the food used in temple offerings.

Who it was written to

The people of Judah and Jerusalem, with special calls to the priests and elders to gather everyone for a public fast and prayer.

Why it was written

Joel treats the locust disaster as a warning sign of the 'day of the LORD', a phrase the prophets use for a coming time when God acts decisively to judge wrong and set things right. He calls the people to turn back to God, who he describes as gracious and compassionate, and then announces that God will restore the land and one day pour out his Spirit on all kinds of people. That promise of the Spirit is quoted in the New Testament book of Acts, chapter 2, where the apostle Peter says it is being fulfilled as the first followers of Jesus begin speaking in other languages.

Big themes

The day of the LORD · Turning back to God with your whole heart · God restoring what was lost · God's Spirit for everyone

How it is laid out

A land stripped by locusts and drought (1)

The day of the LORD comes like an invading army (2:1-11)

A call to come back to God (2:12-17)

God promises to restore the land (2:18-27)

God's Spirit poured out on all people (2:28-32)

Judgment on the nations and a safe home in Zion (3)

A tip for reading it

Chapter 2 describes a terrifying army in language that sounds like locusts, and scholars disagree whether it means the locusts, a human army, or both. Chapter 3 is harsh: it accuses the nations of selling Judah's children into slavery, describes God gathering them for battle and judgment, and turns the famous image of beating swords into plowshares around, calling for plowshares to be beaten into swords. Hebrew Bibles split the book into 4 chapters, so 2:28-32 there is chapter 3 and chapter 3 is chapter 4.