Paul quoted from Joel 2 in his famous Pentecost message. Yet, there are portions of Joel’s prophecy that deserves highlighting because of the common misunderstanding and application of Joel’s prophecy in spite of Peter’s explanation/application of the prophecy to Pentecost. The major reason Peter quotes it on Pentecost is that Joel’s prophecy actually points to the events of Jesus’ crucifixion, resurrection, and Pentecost. But many misapply the prophecy to a future “last days” fulfillment.
Peter said that the Holy Spirit has been poured out. The Spirit empowers us to fulfill Christ’s mission.