The prophet Joel (Jehovah is God) is, in some ways, typical of other Old Testament prophets and yet is unique among the prophets as well. We know nothing of him personally other than he was the son of Pethuel (sincerity of God), of whom we likewise know nothing.
The 73-verse prophecy of Joel is divided neatly in half. In Joel 1:1-2:17 (37 verses) it is the prophet who speaks and from Joel 2:18-3:21 (36 verses) it is Jehovah who does the speaking. The theme of this book is “the day of the Lord,” a phrase which appears five times (1:15; 2:1, 11, 31, 3:14). This phrase is used throughout the Bible to signify God’s judgment and punishment of the wicked. The apostle Peter spoke of the last “day of the Lord” at the end of the world where the final judgment will take place with everlasting results (2 Pet. 3:10-13).
The occasion of Joel’s prophecy is a devastating infestation of locusts that had decimated the vegetation of Judah. Joel used this devastating plague to warn against an even greater invasion. A foreign army would one day invade their country and exercise the judgment of God against His rebellious people and subjugate them unless they repented of their wickedness and rebellion.
In Joel’s prophecy, we find one of the most eloquent entreaties in all of scripture as the prophet implored his countrymen to “…rend your heart, and not your garments, and turn unto the LORD your God…” (Joel 2:13). The rending (tearing) of one’s garments was an outward display of sorrow and grief in ancient times (Gen. 37:34; Job 1:20). However, God was not interested in a superficial display but rather a genuine sign of true repentance (cf. Matt. 3:8)
In Peter’s great sermon on the Day of Pentecost (Acts 2), the apostle invoked the names of two Old Testament characters. One was the great King David, who was also the sweet psalmist of Israel. Peter would add “prophet” to the list of the great king’s credentials (Acts 2:30). The other was Joel. Peter declared that the amazing thing they were witnessing that day, which was that everyone was able to hear “the wonderful works of God” proclaimed in their own language was a fulfillment of the prophecy of Joel (Acts 2:8, 16; cf. Joel 2:28-32). From there Peter recited this prophecy, which was actually the words that Jehovah spoke, but that Joel recorded. In the last days, Jehovah would pour our His Spirit upon “all flesh” (Joel 2:28; Acts 2:17). The people on Pentecost witnessed the result of the Spirit being poured out as the apostles “…began to speak with other tongues, as the Spirit gave them utterance” (Acts 2:4). Not everyone would receive this literal “pouring out” of the Spirit, but “all flesh” would be beneficiaries of it.
Joel also records Jehovah’s judgment of the nations (Joel 3:1-16). Jehovah speaks of these nations being ripe with wickedness and that multitudes would be gathered “in the valley of decision” to receive divine judgment (v.14). The Lord Jesus would refer to His second coming as a judgment of the nations where He, as King, will gather all nations and then separate them as a shepherd separates the sheep from the goats with the sheep on the right hand and the goats on the left (Matt. 25:31-46).
The prophecy of Joel ends with Jehovah’s pronouncement of His dwelling in Zion. Jehovah’s reference to His “holy mountain” (3:17) is assuredly a reference to spiritual Zion—the church of Christ established in Jerusalem. Isaiah and Micah also referred to the future church as being the mountain of the LORD’s house (Isa. 2:2; Mic. 4:1).
We make one final observation concerning the use of the word “afterward” (Joel 2:28). In recounting this portion of Joel’s prophecy where Jehovah Himself promised to pour out His Spirit upon all flesh, Peter rather used the phrase, “in the last days” (Acts 2:17). Although many today are looking for signs of “the last days” or “the end times,” Peter made it clear that as he was speaking “the last days” had begun. The institution of the church of Christ on the Day of Pentecost constituted the beginning of the last days. This was confirmed by the writer of Hebrews who stated, “God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets, Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds” (Heb. 1:1-2—emph. RR). Despite its relative brevity, Joel’s prophecy had particular significance for the people of his own time and continues to have ramifications for all of mankind until the end of the world.