Summary: God planted Israel - both the old and the new - to bear fruit. At harvest time, only the good fruit will be kept.
This passage is another tough one, dealing with wrath and judgment and punishment. And as you know scaring people into the kingdom is not my favorite style, although it may very well be that fear is a better motivator for some people than it is for me. But in our day and age, it’s more likely, I think, that people will respond to hellfire and brimstone sermons by simply deciding not to believe in eternal punishment. Recent surveys show that far more people believe in heaven than in hell, and most of those who do believe are sure they’re headed for heaven, because after all they’re pretty good people, and the God of love we know through Jesus couldn’t possibly be that mean. In fact,"God so loved the world that he gave his only Son, so that everyone who believes in him may not perish but may have eternal life. Indeed, God did not send the Son into the world to condemn the world, but in order that the world might be saved through him. [Jn 3:16-17]
But this same Jesus who came to seek and save the lost is also the one presiding over the great harvest at the end of the age. Hear how John describes him: “Then I looked, and there was a white cloud, and seated on the cloud was one like the Son of Man, with a golden crown on his head, and a sharp sickle in his hand! [v. 14] How do we reconcile these two seemingly contradictory pictures?
If we just look at this chapter of Revelation on its own, it doesn’t seem like the same God at all. Is this the good shepherd who went out searching for the lost sheep? Is this the same loving father who welcomed home the prodigal son without a word of blame or demand for repayment?
Yeah. It is. And the key is in the idea of harvest. There are a lot of passages in Scripture which liken God to a farmer, or a gardener, or to the owner of a vineyard. And there are really two harvests in this one passage. The first is of wheat, and the second is of grapes. And it looks very much as though the harvested grain represents believers, and the harvested grapes represent unbelievers. ”The hour to reap has come,” said the angel, “ because the harvest of the earth is fully ripe." So the one who sat on the cloud swung his sickle over the earth, and the earth was reaped. [v. 2-3]
Now some people are puzzled by this picture because if the one holding the sickle is Jesus, what is he doing taking orders from a mere angel? But if you recall Jesus’ words to his disciples when they asked him when the end would come, he said, "about that day and hour no one knows, neither the angels of heaven, nor the Son, but only the Father. [Mt 24:36] The angel isn’t giving Jesus orders, he’s just a messenger announcing the time.
So Jesus' part in the harvest is to gather in his own - the ones whom he recognizes, the sheep who know his voice, to mix the metaphors again. “The one who rejects me and does not receive my word ... on the last day the word that I have spoken will serve as judge.” [Jn 12:47-48] Note that Jesus isn’t the one who does the rejecting.