Joel begins by describing a devastating locust plague upon Judah. The destruction of the locusts pictures the total destruction that could come by an enemy army. This final and devastating destruction to the land and the nation is called the day of the Lord. This becomes the dominant theme to the end of the book, where we get descriptions of several events surrounding the eschatological “The Day of the Lord,” the period and events at the Second Advent of Christ. One of those significant events is the prediction of the pouring out of the Holy Spirit upon God’s people. Peter quotes from Joel regarding that event in relaton to the Baptism of the Holy Spirit in Acts 2.