God promises to pour out his spirit
Joel uses a terrible plague of locusts as a picture of the coming Day of the Lord, in which a northern army would cause great devastation in Judah. The only hope is that if the nation repents, God said he would “restore to you the years that the locust hath eaten,” and pour out his spirit. On the day of Pentecost, Peter said the followers of Christ who were filled with the Holy Spirit and speaking in with other tongues were not drunk, but “this is that which was spoken by the prophet Joel" (Acts 2:15-21).
And it shall come to pass afterward,
that I will pour out my spirit upon all flesh;
and your sons and your daughters shall prophesy,
your old men shall dream dreams,
your young men shall see visions:
And also upon the servants and upon the handmaids
in those days will I pour out my spirit.
And I will shew wonders in the heavens and in the earth,
blood, and fire, and pillars of smoke.
The sun shall be turned into darkness,
and the moon into blood,
before the great and terrible day of the LORD come.
And it shall come to pass,
that whosoever shall call on the name of the LORD
shall be delivered:
for in mount Zion and in Jerusalem shall be deliverance,
as the LORD hath said,
and in the remnant whom the LORD shall call.