24 He put before them another parable: “The kingdom of heaven may be compared to someone who sowed good seed in his field; 25 but while everybody was asleep, an enemy came and sowed weeds among the wheat, and then went away. 26 So when the plants came up and bore grain, then the weeds appeared as well. 27 And the slaves of the householder came and said to him, ‘Master, did you not sow good seed in your field? Where, then, did these weeds come from?’ 28He answered, ‘An enemy has done this.’ The slaves said to him, ‘Then do you want us to go and gather them?’ 29 But he replied, ‘No; for in gathering the weeds you would uproot the wheat along with them. 30 Let both of them grow together until the harvest; and at harvest time I will tell the reapers, Collect the weeds first and bind them in bundles to be burned, but gather the wheat into my barn.’”
Why didn't Jesus clean up the whole mess when He came? Certainly that was the expectation of what the Messiah of Israel would do when he came. If the Messiah, the true King of Israel, came to establish his kingship, then it was a matter of common sense that the enemies of this kingship would be dealt with. The disciples of Jesus were clearly under this impression.
But as we know, the disciples of Jesus were under many false impressions about the Messiah and the nature of the Kingdom of God. For one, they were initially mistaken about the scope of Jesus' Messiahship. The scope was not coterminous with the boundaries of Israel. The scope of Jesus' Messiahship was far greater: it covered all of creation! Both the fallen parts (i.e., our natural world) and the unfallen parts (e.g., the angelic realm). As Abraham Kuyper once said, "There is not a square inch in the whole domain of our human existence over which Christ, who is sovereign over all, does not cry, Mine!"
The disciples were also mistaken about when and how the Kingdom of God would be established. They expected now and swiftly and sweepingly now. The now aspect was partly correct. When Jesus came, the Kingdom of God broke in, in an unmistakable way with healing, deliverance, miracles, and other signs and wonders. But the Kingdom of God did not come in its complete fullness. Some aspects still had to wait, like the resurrection of the dead (i.e., all humanity) and the final overthrow of the evil one. The Kingdom of God that was inaugurated still had to wait for its consummation.
In the meantime ... (Jesus' parable above) ... the wheat and the weeds/tares grow together in the field.
The "weeds" (probably darnel [lolium temulentum]) look very much like wheat while it is young and growing. Later, the tares/weeds can be distinguished from the wheat. The tares are not unbelievers in the professing church (as commonly interpreted in many church traditions). We learn from Jesus that the "field" is the world (not church) in verse 38. The parable is teaching us that in this world the people of God's kingdom will live side by side with people of the evil one.
The sifting, the setting apart of the wheat from the tares, will come on the Day of Judgment, when Jesus the Messiah comes again.
Why this teaching? First, to deal with the false expectation that Jesus will sift -- set apart -- the wheat from the tares now. Second, to inform the disciples that as the Kingdom of God grows, don't be surprised that the kingdom of darkness will grow alongside of it as well. Don't be discouraged. The final reckoning and the final setting to rights will come, in time. In the meanwhile, our job is to advance the Kingdom of God!
Let's pray: Lord Jesus, we confess your Lordship/Messiahship over all of creation. We trust in your timing for all things. We thank you that your Kingdom is still advancing. We pray that the strength of darkness in some places will not mislead us into thinking that you are somehow weak or overpowered. Help us to be encouraged that justice and the day of judgment will certainly come, so that you and your cause will be vindicated and that you will be glorified by all. In your name, amen.