Joel is a prophet to Judah and is writing during a time when locusts are eating all the crops. Chapter 1 describes the destruction from the locusts. In our chapter today, Joel tells them this is only a small indication of the destruction that will come in “the day of the Lord.” There is a day coming when God’s hand of protection will be removed and evil will become everyone’s oppressor. Jesus also talks about this in Matthew 24.
Sometimes when the people are suffering, God sends a prophet to say God is still in control; sometimes the prophets say God will eventually forgive; Joel says things will get much worse. It’s not an uplifting message, but we should be encouraging people to come to Christ so they can avoid God’s wrath.