Joel 3:13

"Put ye in the sickle; for the harvest is ripe: come tread ye; for the winepress is full, the vats overflow; for their wickedness is great.

Revelation 14:14-20 appears to be founded entirely upon this conception introduced in these few verses of Joel. See CRE for extensive comment on this, for practically all of it is applicable here.

This verse surely supports the view that the "mighty ones" from above, spoken of as "coming down" in the preceding verse, must be the angels of God, for, "Down to N.T. times the eschatological harvesters are usually the angels (Matthew 13:39; Revelation 14:14-20)."[23] This double figure of the judgment under the imagery of the grain harvest and of the grape harvest suggests much important truth regarding God's final judgment of humanity. It will come at a time when human wickedness has run its course, borne its fruit, and arrived at a state where there is nothing else left to do except to reap it! There has been some refinement of the double figure by subsequent sacred authors who used the treading of the winepress as particularly indicative of God's wrath, and the gathering of the wheat into the garner as indicating the salvation of the righteous.