The Abiding Value of the Book.
The prophecy of Joel was probably occasioned by the devastating incursion of a huge swarm of locusts ( 1:2–12 ), but the oracles are essentially the utterances of a man whose word has the creative power to make things happen (see JOEL 1:2–4 ). Many incidents of Israelite history prove that prophetic discourse was a means to change destinies. It aroused fear and repulsion when it was gloomy, and happiness when it promised a bright future. Joel's prophetic word creates calamities; it is effective when it describes the day of the Lord, and when it indicates the path to salvation.
In that sense, Joel stands as a creative word which overrules all contingencies. Not dependent on a particular event, it is non-historical and can exercise its powers anywhere and at any moment. Later readers internalized this and found that it led them from suffering and feelings of deprivation, through repentance and prayer, to the joy of renewed communion with the merciful Lord.