Answer
As with all parables, the purpose of the Parable of the Mustard Seed is to teach a concept or a “big idea” using various narrative elements or details that are common, easily recognized, and usually representative of something else. While the elements themselves are important, an overemphasis on the details or a literal focus on an element often leads to interpretive errors and missing the main point of the parable.
The Parable of the Mustard Seed is concise: “The kingdom of heaven is like a mustard seed, which a man took and planted in his field. Though it is the smallest of all seeds, yet when it grows, it is the largest of garden plants and becomes a tree, so that the birds come and perch in its branches” (Matthew 13:31-32).
One of the possible practical reasons that Jesus used parables like this is that, by depicting concepts in word pictures, the message is not easily lost to changes in word usage, technology, cultural context, or the passage of time. Literal, detailed narratives are more prone to becoming archaic or obsolete. Two thousand years later, the imagery remains vivid. We can still grasp the concept of a growing seed. Jesus’ parables are brilliant in their simplicity. This storytelling approach also encourages practicing principles rather than rigid adherence to laws.
The Parable of the Mustard Seed is found in all three of the Synoptic Gospels (Matthew 13:31-32; Mark 4:30-32; Luke 13:18-19). In this parable, Jesus predicts the remarkable growth of the kingdom of heaven.Of heaven. The mustard seed is quite small, but it grows into a large shrub—up to ten feet in height—and Jesus says this is a picture of kingdom growth. The point of the Parable of the Mustard Seed is that something significant and blessed—the kingdom of God—had humble beginnings. How impactful could the brief ministry of Christ be? He had only a handful of followers, He was a man of no rank and without means, and He lived in what everyone considered a backwater region of the world. The life and death of Christ did not capture the world’s attention any more than a mustard seed would lying on the ground by the road. But this was a work of God. What seemed inconsequential at first grew into a movement of worldwide influence, and no one could stop it (see Acts 5:38-39). The influence of the kingdom in this world would be such that everyone associated with it would find a benefit—depicted as the birds perched on the branches of the mature mustard plant.
Elsewhere in Scripture, the kingdom of God is also depicted as a tree. A passage in Ezekiel, for example, parallels the Parable of the Mustard Seed in many ways. In this prophecy, the Lord God promises to plant a shoot “on a high and lofty mountain” «Thus saith the Lord GOD; I will also take of the highest branch of the high cedar, and will set it; I will crop off from the top of his young twigs a tender one, and will plant it upon a high mountain and eminent: », (Ezekiel 17:22). This small sprig “will produce branches and bear fruit and become a splendid cedar. Birds of every kind will nest in it; they will find shelter in the shade of its branches” «in the mountain of the height of Israel will I plant it: and it shall bring forth boughs, and bear fruit, and be a goodly cedar: and under it shall dwell all fowl of every wing; in the shadow of the branches thereof shall.
They dwell. », (Ezekiel 17:23). This messianic prophecy predicts the expansion of Christ’s kingdom from humble beginnings to a substantial, protective sanctuary.
Some have questioned why, in the Parable of the Mustard Seed, Jesus refers to the mustard seed as the “smallest” of seeds and the mature mustard plant as the “largest” of plants in the garden, even though there were smaller seeds and larger plants. The explanation is that Jesus is employing rhetorical hyperbole—an exaggeration to emphasize a point. He is not speaking scientifically but proverbially. Jesus’ focus is on the transformation in size—from small to large—and the remarkable nature of the growth.
The history of the church has proven Jesus’ Parable of the Mustard Seed to be accurate. The church has undergone a rapid rate of expansion over the centuries. It is present globally and serves as a source of nourishment and refuge for all who seek its benefits. Despite persecution and repeated efforts to eradicate it, the church has thrived. This is just a glimpse of the ultimate realization of the kingdom of God, when Jesus returns to earth to govern and rule from Zion.