Summary
A Mustard Seed, Yeast and Flour
In two short parables in Matthew 13:31-33, Jesus describes the kingdom of heaven—first as a mustard seed sown in a field, then as yeast a woman mixes into three measures of flour. To grasp what he is teaching, we must first ask what "kingdom" means on his lips. A kingdom is ordinarily a territory ruled by a king, and in one sense the whole creation belongs to God who made it. But when John the Baptist and Jesus both preach, "Repent, for the kingdom of heaven has come near," and when the Lord's Prayer asks "thy kingdom come," something more is in view. The kingdom of God is the reign and rule of God by the Holy Spirit in the hearts of believers, and the visible expression of that reign is the church.
The parable of the mustard seed describes how this kingdom grows. Its beginnings could hardly be more humble: the founder of the church born in a stable and laid in a feeding trough; shepherds—at the bottom of the social order—first to hear the angelic announcement; ordinary fishermen and tradesmen called as apostles; only a small gathering present at the first Pentecost after three years of teaching and miracles. From that tiny seed grew the great tree whose branches now reach across the globe. The strength of this tree is not its institutional weight but its foundation. When Jesus says in Matthew 16:18, "on this rock I will build my church, and the gates of hell shall not prevail against it," the rock is the gospel confessed—Jesus is Lord and Savior. Because the church is his and rests on that confession, predictions of her demise have always proven false.
The parable of the yeast describes how the kingdom acts. A small amount of leaven, hidden in the dough, transforms the whole loaf. So the church, planted in the world, leavens everything around it. The historical fingerprints of the gospel are everywhere: the abolition of slavery, the elevation of women to equality, the valuing of life from conception to natural death, the care of the disabled, the founding of hospitals (notice how many bear Christian names), and movements toward prison and justice reform. Yet the greatest leavening of all is the proclamation of the gospel itself, because that alone has eternal consequences—announcing that sins are atoned for in Christ, the wrath of God satisfied, sinners reconciled through his blood, the tomb empty, the baptized claimed as God's own.
Citizens of this kingdom face a perennial temptation: to domesticate the faith, to keep it small, private, tucked safely "deep down inside." Luther said faith is a living, busy, active, mighty thing—and he compared it to an elephant. An elephant is the largest land animal, swift, tireless, immensely strong, and useful for moving what nothing else can move; yet even in captivity it can never truly be tamed. So it is with saving faith. As James writes in James 2:17, "faith by itself, if it has no works, is dead"—not because works save, but because real faith cannot help expressing itself. God will not allow the faith he plants in us to be domesticated into something safe and silent.
To Pilate, Jesus said, "My kingdom is not of this world" John 18:36, pointing to the Spirit's reign in human hearts. Calvin captured the Christian's calling well: to make the invisible visible. The invisible kingdom becomes visible in how we steward time, talent, and treasure; in our families, homes, workplaces, and conversations; in how we speak to and act toward one another. Rather than lamenting the state of the world, the people of God are summoned to leaven it—small as a mustard seed at the start, mighty as an elephant in expression, growing into the great tree God himself is building. This is the substance of “A Mustard Seed, Yeast and Flour”: the kingdom that begins hidden and humble, and by the Spirit's work transforms everything it touches.
Video citations
- “A Mustard Seed, Yeast and Flour” 10-17-21 — What you're open your Bibles, please, with me this morning to Matthew the 13th chapter. If you're using a few edition of Holy Scripture, you're going to find that on page 13 in the New Testament.…