Joel 3:13
Put ye in the sickle, for the harvest is ripe: come, get you down; for the press is full, the fats overflow; for their wickedness is great. Put ye in the sickle, for the harvest is ripe: come, get you down; for the press is full, the fats overflow; for their wickedness is great.
The ripe harvest and the full press with overflowing vats mean that wickedness has become great and stands ready for judgment. That ripeness is the condition of God's persecutors, whose evil is mature and prepared for reaping. In its setting the prophecy foretells the time when God's voice shakes the heavens and the earth and His wrath falls upon those who persecute His people by enforcing the mark of the beast. Those who turned away from what the Lord spoke when His voice shook the earth will then confess their fatal error.
They will at that time see the importance of the Sabbath as the seal of the living God. The harvest also pictures the work of saving souls, in which God's people are to be like sharp sickles in the harvest field. God hears prayer and reveals His power by making such laborers effective instruments in His work.
The ripe harvest comes with too few laborers, so the call is for decisive reaping by workers made ready to bring the message. Believers who know the truth are to pray that God will send workers to carry the message to those who have not heard it and who are in spiritual darkness. That sending includes people in cities and other places, and those who pray are also to do what they can to support the workers and themselves reflect light to others.