The Book of Joel - Introduction
This prophecy is rich in apocalyptic imagery and strongly eschatological in tone. It was composed about 400 B.C.. Its prevailing theme is the day of the Lord.
A terrible invasion of locusts ravaged Judah. So frightful was the scourge that the prophet visualized it as a symbol of the coming day of the Lord. In the face of this threatening catastrophe, the prophet summoned the people to repent, to turn to the Lord with fasting and weeping. They were ordered to convoke a solemn assembly in which the priests would pray for deliverance. The Lord answered their prayer and promised to drive away the locusts and bless the land with peace and prosperity. To these material blessings would be added an outpouring of the spirit on all flesh. St. Peter, in his first discourse before the people at Pentecost (Acts 2, 16–21 ), sees in the coming of the Holy Spirit the fulfillment of this promise ( 1, 1–3, 5 ).
The concluding poem pictures the nations gathered in the Valley of Jehoshaphat, where the Lord is about to pass judgment. Israel's enemies are summoned to hear the solemn indictment; their evil deeds are at last requited. The tumultuous throng assembled in the valley of decision is made up of the enemies of God and they face inevitable destruction. The oracle changes abruptly from the terrifying image of judgment to a vision of Israel restored and forever secure from her enemies. God is both the vindicator of his people and the source of their blessing ( 4, 1–21 ).