Traditionally, Joel is called the prophet of Pentecost, since his prophecy of the outpouring of the Spirit (see Joel 2:28-32) is quoted by Peter in Acts 2:16-21 to explain the outpouring of the Holy Spirit at Pentecost. The occasion of his prophetic message was a devastating locust plague, which he interpreted as being a foreboding about the Day of the Lord, when God would act directly to punish his people for their sins. Joel calls upon the people of Judah to repent, promising that repentance will cause the Lord to pour out his Spirit and his blessings upon his people. 

—Henrietta Mears

Source: This content is from What the Bible Is All About, written by Henrietta Mears. Copyright © 1953, 2011 by Gospel Light. Copyright assigned to Tyndale House Publishers, 2015. Used by permission of Tyndale House Publishers, a division of Tyndale House Ministries, Carol Stream, Illinois 60188. All rights reserved.  

The first half of the book [of Joel] describes how God fought against his own people to make them honor him alone. And the second half of the book describes how he will fight against the nations who refuse to honor him alone.

…So Joel sees two things coming as the day of the Lord approaches: one is a great outpouring of the Holy Spirit (2:28, 29), and the other is a terrible time of divine judgment. He had fought against his own people in the past to lead them to salvation. He will fight against the nations in the future who reject his salvation and his people… Joel sees a future with two sides: salvation and blessing for those who call on the name of the Lord, but judgment and destruction for the people who go their own way. 

…The purpose of God in the historical locust horde and the purpose of God in the final day of the Lord are the same: to make known that he alone is God and is to be loved and worshiped and served above all things.

—John Piper

Source: By John Piper. © Desiring God Foundation. Source: desiringGod.org. Quoted from his message, “The Locust Horde and the Day of the Lord.”

From Bibles.net: We have linked to this message in the Tough Questions section, and encourage you to listen to the message!

In typical prophetic form, Joel gives his readers both the bad news of God’s judgment and the good news of his promised deliverance. The book contains a description of a dramatic judgment on God’s people through a devastating plague of locusts. This serves as a warning of the great “day of the Lord” at the end of time. Joel also includes one of the Old Testament’s most significant promises regarding the future coming of the Holy Spirit. 

Both the judgment and the promise remind us of our desperate need for God’s help. The judgment that our sins deserve is far worse than a plague of locusts. The promise of the Spirit reminds us that the help we need is nothing less than supernatural. Through the ministry of Jesus Christ, the requirements of judgment and of supernatural provision have both been met. Jesus took upon himself the plague of judgment for our sins (2 Corinthians 5:21; 1 Peter 2:24) and then promised (John 14:16) and provided (Acts 2) the gift of the Holy Spirit. 

—Timothy Witmer

Source: Content adapted from the ESV Gospel Transformation Study Bible. Quoted from the article “The Gospel in Joel,” which you can find on Crossway.org; used with permission.

In the worst times that can ever happen, there is still salvation for men. When day turns to night, and life becomes death, and the staff of life is broken, and the hope of man has fled, there still remains in God, in the person of his dear Son, deliverance to all those who will call upon the name of the Lord. We do not know what is to happen: reading the roll of the future, we prophesy dark things; but still this light shall always shine between the rifts of the cloud-wrack: “Whosoever shall call on the name of the Lord shall be delivered” (Joel 2:32 KJV).  

…To “call on the name of the Lord,” is briefly to pray a believing prayer; to cry to God for his help, and to leave yourself in his hands. This is very simple, is it not? There is no cumbersome machinery here, nothing complex and mysterious. No priestly help is wanted, except the help of that great High Priest, who intercedes for us within the veil. A poor, broken heart pours its distress into the ear of God, and calls upon him to fulfil his promise of help in the time of need—that is all. Thank God, nothing more is mentioned in our text. The promise is—“Whosoever shall call on the name of the Lord shall be saved.” 

…When the need of deliverance shall apparently increase, the abundance of salvation shall increase with it. Fear not the direst of all wars, the bitterest of all famines, the deadliest of all plagues; for still, if we call upon the Lord, he is pledged to deliver us. This word of promise meets the most terrible of possibilities with a sure salvation. 

…This way of salvation, by calling upon the name of the Lord, glorifies God. He asks nothing of you but that you ask everything of him. You are the beggar, and he is the benefactor. You are in the trouble, and he is the Deliverer. All you have to do is to trust him, and beg of him. This is easy enough. This puts the matter into the hands of the Lord, and takes it out of your hands. Do you not like the plan? Put it in practice immediately! It will prove itself gloriously effectual. 

—Charles Spurgeon 

Source: Spurgeon, Charles Haddon. “A Free Grace Promise.” The Spurgeon Center (October 11, 1888).

From Bibles.net: We encourage you to read the whole message listed above where we retrieved this quote. It would be a wonderful message to read as a family over the course of a few days. You will be so blessed by listening to Charles Spurgeon teach us to call on the name of the Lord.

“The grain is destroyed, the wine fails, and the oil languishes” (Joel 1:10 ESV). It is difficult for non-Mediterranean readers to absorb the force of this. For British people an equivalent might be bread, butter, and tea. For Americans it might be hamburgers, coffee, and gasoline. In China and many countries in the East, the grain concerned would be rice. Grain, wine, and oil were necessary for the staple diet of Mediterranean countries—the grain to make bread; the fruit of the vine as daily drink; olive oil for cooking, cleansing, soothing, lighting, and much else besides.  

—David Prior  

Source: Prior, David. The Message of Joel, Micah, and Habakkuk. The Bible Speaks Today. Downers Grove, IL: InterVarsity Press, 1999.

Joel’s chronological placement can make you think of him as the prophet of prophets, the CliffsNotes of the prophets… He’s taking all the information that the prophets have thought of in Ezekiel and Zephaniah and Isaiah and Amos and he quotes all of them throughout his whole book. He’s saying, “…If you’re going to take everything all the other prophets are saying about the Day of the Lord and the way that we should respond to natural disaster and expect coming judgment, then here it is in three chapters.”

The fact that there’s so few details about Joel’s life or when the book of Joel was written is by virtue of the fact that he’s giving you the CliffsNotes of all the major and minor prophets. That, and he’s wanting his book to be a repeatable liturgy that people could go through regardless of time. Anytime there’s a natural disaster, you could read Joel. Any time an enemy army is coming against you, whether they are locusts or a physical one, you could read Joel, lament, repent, and ask the Lord for mercy.

Joel has a practical use. Joel has a usefulness in my life as a meditation during a time of national mourning over natural disasters.  

—Spoken Gospel  

Source: David Bowden and Seth Stewart in the Spoken Gospel podcast, “Joel 1:1-2:27: The Day of the Lord (Is COVID God’s Judgment?),”published at spokengospel.com.