And He was saying, “The kingdom of God is like a man who casts seed upon the soil; 27 and he goes to bed at night and gets up by day, and the seed sprouts and grows—how, he himself does not know. 28 The soil produces crops by itself; first the blade, then the head, then the mature grain in the head. 29 But when the crop permits, he immediately puts in the sickle, because the harvest has come.” — Mark 4:26-29, NASB

The parable is found in Mark, preceding and loosely related to the parable of the mustard seed. It contrasts man’s limitations with God’s absolute sovereignty in the matters of spiritual growth and salvation.

In the analogy, a man sows seed upon the soil, or spreads the word of God in the world. As he goes about his life’s routine, the seed develops on its own without further assistance, in the same way that the gospel fosters saving faith in a new believer. How this happens is beyond the man’s comprehension. Eventually, a fully developed crop is produced. The man has not produced the crop, but participates in the harvest, just as evangelizing Christians share in the blessing of the saved and sanctified, the fruits of God’s holy work.

Self-acting and imbued with life itself, a seed is a miraculous creation of God. Humans cannot create one from scratch nor do much to make one function beyond sowing it. Spurgeon once made the point while preaching the parable of the mustard seed:

Summon your chemists; bring them together with all their vessels and their fires. Select a jury of the greatest chemists now alive, analytical or otherwise, as you will. Learned sirs, will you kindly make us a mustard seed? You may take a mustard seed, and pound it and analyze it, and you may thus ascertain all its ingredients. So far so good. Is not your work well begun? Now make a single mustard seed. We will give you a week. It is a very small affair. You have all the elements of mustard in yonder mortar. Make us one living grain; we do not ask for a ton weight. One grain of mustard seed will suffice us. Great chemists, have you not made so small a thing? A month has gone by. Only one grain of mustard seed we asked of you, and where is it? Have you not made one in a month? What are you at? Shall we allow you seven years? Yes, with all the laboratories in the kingdom at your service and all known substances for your material and all the world's coal beds for your fuel, get to your work. The air is black with your smoke and the streams run foul with your waste products; but where is the mustard seed? This baffles the wise; they cannot make a living seed. No; and nobody can make a Gospel, or even a new Gospel text.*

Such are the mechanisms of God, among which the power of His holy word is paramount. Once seed has been planted the farmer may tend his crop, seeking to make conditions as favorable as he can for growth, but it is God who gives the increase and produces the harvest. Likewise, man cannot produce his own or others’ salvation. All one can do is believe in the Lord Jesus and proclaim the gospel message. God will handle it from there according to His will.

As the plant develops gradually over time, so does the work of the Holy Spirit transform the nature of the believer. Sometimes people do not respond immediately to the word of God, and that should not discourage an evangelizing Christian. The parable’s delineation of the plant’s growth cycle—first the blade, then the head, and finally the mature grain—shows a gradual progression. In grace, a process is at work apart from man’s effort, growing and producing a harvest in its own due time. The example of the growing seed also reflects progressive sanctification, through which the believer, having put on the new self, gradually sheds his sinful nature to reflect God’s nature.

There are efforts among Bible scholars to draw parallels or unify our Lord’s agricultural parables. Some of these linkages fit and some do not, but it is always best to consider each parable within its own context. For instance, unlike the parable of the tares, in which the sower of good seed is generally taken to be Jesus, here the sower is clearly a believer spreading the Word of God, attempting to plant the seed of the gospel in the hearts of others. The non-divine nature of the sower is made plain in the fact that “he himself does not know” how the seeds sprout and grow. To identify the sower as Jesus, citing the Lord’s self-imposed human limitations while in His earthly body, is to overreach the meaning.

Additionally, the harvesting described in the parable of the growing seed does not serve the same purpose as that in the parable of the tares, which symbolizes God’s end-time judgments. Instead, when the “mature grain” is finally produced, a believer’s heart has been transformed and is capable of producing fruit and glorifying God.

While the parable of the sower focuses on man’s condition and response in receiving the word of God, the parable of the growing seed emphasizes the divine power of the word itself and man’s need to trust in that power. While He uses human means to sow the gospel, spiritual growth comes from God alone through the work of the Holy Spirit.

The same man who sows the seed in verse 26 also harvests the grain in verse 29. This also could become a stumbling block because of God’s typical association in scripture as the harvester, as well as the example from the tares where it is God’s angels who reap souls. It may be helpful to refer to the context of John 4:35-36, shortly after Jesus had encountered the Samaritan woman at the well. Struck by His words and wondering aloud if He were the Christ, she goes into the nearby city to tell everybody. As Jesus was later speaking to the disciples and declaring the fields being white for harvest, He was actually describing the scores of people who had heard her testimony and were now coming up from the city to see Him. It was not the disciples who planted the seed of truth through the promise of “living water” in the woman’s heart; they were out buying food when Jesus had been talking to her. But now they were receiving the privilege of participating in a harvest of previously lost souls in which they had spent no effort, just like the harvesting of grain by the man in the parable. It is the responsibility of Christians not only to sow or share the word of God, but to harvest as well—to
receive, encourage and strengthen new believers through communion with the other brethren once grace has done its work.

As sowers of God’s word, Christians must trust in the power of the gospel seed and the sovereignty of the Lord in bringing the harvest. He will finish what He started.

Quotation reference:
* Spurgeon, C.H.; The Mustard Seed: A Sermon for the Sabbath-School Teacher (Sermon #2110), Oct. 20, 1889