A prophet told to marry an unfaithful woman, Gomer, as a living picture of Israel's unfaithfulness to God and God's refusal to give up on her.

Hosea spoke to the northern kingdom in its last decades. Gomer leaves him, and he is told to go and buy her back. The book uses the language of marriage and betrayal for idolatry, and it holds together fierce anger and tender love: "How can I give you up, Ephraim?"

Hosea 11:8

A devastating plague of locusts, which Joel treats as a warning of the coming day of the LORD and a call to repent, followed by a promise that God will pour out his Spirit on all people.

The promise that sons and daughters, old and young, and even servants will receive the Spirit is the passage Peter quotes on the day of Pentecost in Acts 2, when the Spirit comes on the first disciples. Joel's date is uncertain, which matters less than for most prophets because the message does not depend on it.

Joel 2:28-29

A shepherd from Judah sent to the prosperous northern kingdom to condemn its injustice to the poor and its comfortable religion.

Amos spoke during a time of wealth and confidence, around 760 BC, and told the rich that their feasts and worship meant nothing to God while they crushed the needy. His line "let justice roll down like waters, and righteousness like an ever-flowing stream" was quoted by Martin Luther King Jr. in the "I Have a Dream" speech.

Amos 5:24

God's judgment on Edom for gloating over and joining in the fall of Jerusalem.

It is the shortest book in the Old Testament, a single chapter. Edom was descended from Esau, Jacob's twin, so the feud goes all the way back to Genesis. The charge is that Edom stood by, and then helped, as its brother nation was destroyed.

Obadiah 1:10-12

A prophet who runs from God's command to preach to Nineveh, the capital of Israel's enemy Assyria, is swallowed by a great fish, and then is furious when the city repents and God spares it.

The fish is the famous part, but the point of the book is the last chapter. Jonah ran because he knew God was merciful and did not want his enemies to receive that mercy. The book ends with God asking Jonah a question he never answers: should I not care about that great city? Jesus referred to Jonah's three days in the fish as a sign of his own death and resurrection.

Jonah 4:11

Judgment on the corruption of both Israel and Judah, with hope of a ruler from Bethlehem, and the famous summary of what God requires.

Micah was a younger contemporary of Isaiah. He names Bethlehem, David's hometown, as the birthplace of a coming ruler, which Matthew quotes in the story of the wise men. He also sums up the heart of the law: to do justice, to love kindness, and to walk humbly with your God.

Micah 6:8

The coming fall of Nineveh, the capital of the Assyrian empire, which happened in 612 BC.

It is the other side of Jonah. Over a century after Nineveh repented at Jonah's preaching, Assyria was again notorious for its cruelty, and Nahum announces that God will bring it to an end. For the nations Assyria had crushed, including the destroyed northern kingdom, the book was good news.

Nahum 1:7-8

A prophet arguing with God — first about why he allows injustice in Judah, then about why he would use the even more wicked Babylonians to punish it.

It is unusual because the prophet speaks to God rather than for him. God's answer includes the line "the righteous shall live by faith", which Paul quotes in Romans and Galatians and which became a watchword of the Reformation. The book ends with Habakkuk choosing to rejoice in God even if the crops fail and the herds are gone.

Habakkuk 2:4

The coming day of the LORD as a day of judgment on Judah and the nations, followed by the restoration of a humble remnant.

Zephaniah prophesied during the reign of King Josiah, and his warnings may have helped spark Josiah's reforms. The book's description of judgment is among the most severe in the prophets. It ends in the opposite key, with God rejoicing over his people with singing.

Zephaniah 3:17

A call to the returned exiles, in 520 BC, to stop neglecting the unfinished temple and rebuild it.

The foundations had been laid years earlier, but work had stopped while the people built their own houses. Haggai asks whether it is right for them to live in panelled houses while God's house lies in ruins. The people listen, and work resumes within weeks.

Haggai 1:4

Visions and messages encouraging the returned exiles as they rebuilt the temple, and promises of a coming king.

Zechariah worked alongside Haggai. The second half of the book looks further ahead, and several passages are applied to Jesus in the Gospels, most famously the king coming to Jerusalem humble and riding on a donkey, fulfilled on Palm Sunday. It also mentions thirty pieces of silver, the sum later paid to Judas.

Zechariah 9:9

The half-hearted worship and broken promises of the Jews after the return, and a promise that God would send Elijah before the day of the LORD.

Malachi is the last book of the Protestant Old Testament. Priests were offering blind and sick animals, and husbands were abandoning their wives. The Old Testament ends here waiting: the temple is rebuilt, but the promised king has not come. Jesus later said that John the Baptist was the Elijah who was to come.

Malachi 4:5