The experience of recovery described in the previous verses is remarkable for its richness. Yet the Lord informs his readers that more is to come. They may ask how more could be given. An answer is given in this section when the prophet predicts days of worldwide spiritual blessing. Because we have the Book of Acts we know that Joel prophesied here of what would happen on the Day of Pentecost and afterwards. Therefore he is describing the onset and growth of the Christian church.
Who is speaking in verse 28? Acts 2 tells us that it was the exalted Jesus who poured out the Spirit on those gathered in Jerusalem. So here in Joel, Jesus is speaking before he became incarnate. And he is able to pour out the Spirit on all flesh because he has been exalted to rule over all the earth.
When the Spirit is poured out, all the recipients of the blessing will become prophets (v. 28), that is, they will be able to speak about God and his kingdom (the reference to dreams and visions is another way of saying that they would have prophetic functions). Moreover, the blessing will be given to even the humblest of them, those described as servants (v. 29). This is a great privilege, to be able to speak for God wherever we are.
Who is the Speaker addressing? In verse 28, he refers to ‘your’ sons and daughters and to ‘your’ old men and ‘your’ young men. He is speaking to those who had received the blessings described in the previous verses. Yet they had left the world long before the prophecy began to be fulfilled on the Day of Pentecost. Nevertheless there was a real, living connection between them and the believers of the future. Here is a reminder of the oneness of the people of God.
The coming of the Spirit would be the equivalent in the spiritual world of a cataclysmic change in the natural world (vv. 30-31). We are not expected to regard the depicted changes in a literal manner. Instead, graphic changes in the physical world are used to picture dramatic changes in the development of God’s kingdom.
When the Spirit comes, there will be an increased focus on salvation. He will lead many to call on the name of the Lord and, by doing so, they will escape the judgement of God and live with him in Mount Zion and in Jerusalem. Joel’s readers may not have realised that the Zion and Jerusalem here is not a reference to an earthly location. Instead they are other names for heaven (as Hebrews 12:22 makes clear). We should be glad that we live in the period in which this prophecy about the coming of the Spirit is being fulfilled.