The Mustard Seed and the Yeast: A Kingdom That Grows

Introduction

In Matthew 13:31-33, Jesus tells two very short parables: the mustard seed and the yeast. Two ordinary images (a tiny seed, a bit of fermented dough), to say one truth: the kingdom of God starts small, but it grows and transforms everything it touches. Benjamin, a preacher at Momentum, shows that these parables work on two complementary levels: the kingdom unfolding in the world over 2,000 years, and the kingdom growing patiently inside each disciple. The two perspectives echo each other, because the kingdom only advances outside if it progresses inside.

Sermon Outline

1. The kingdom grows in the world

• 1st-century context: a young rabbi from Nazareth, a dozen ordinary disciples (fishermen, a tax collector), facing the Roman Empire and the major religious movements of the day. No one would have bet a cent on this small group.
• Jesus encourages his disciples: the beginning is humble and unimpressive, but it is intentional. This is how God shows his power, as John Calvin recalls in his commentary.
• Historical fact: within a few centuries, the Gospel spread from Jerusalem to Rome and then throughout the Empire, without internet, without media, without war, just by the power of the Spirit. Today, more than 2 billion people identify as followers of Christ.
• The social fruit of the kingdom: dignity for women and children (the first Christians took in abandoned infants), the first hospitals (Basil of Caesarea, 4th century), medieval monasteries and universities, the fight for the abolition of slavery. Many people today benefit from Christian ethics without suspecting its source.
• Four implications for the Church today: courage in mission, hope when the news is bad, a healthy vision of the Church (small like the eleven at the start, but with the same power), and boldness because the Gospel is still dynamite (Romans 1:16).

2. The kingdom grows in us

• The seed is planted in the ground, the yeast is mixed into the dough: the real question is what happens on the inside of you. The kingdom does not advance around us if it does not first grow within us.
• Patience: a seed does not become a tree all at once, dough does not rise instantly. There are seasons, a path of growth, a respect for the time God takes in you.
• Effort: watering, turning the soil, protecting the seed; kneading, folding, working the dough. As Dallas Willard says, the opposite of grace is not effort, it is merit. We deserve nothing, but we are called to collaborate with the Spirit through reading the Word, prayer, church life, small groups, and discipline.
• Two dangers to avoid: believing you can become a tree too quickly (Paul tells Timothy not to give responsibilities to new converts), and believing you can grow without effort ("the Spirit will do it all"). There is no secret: the great women and men of faith were people of prayer who knew the Word by heart.
• Evaluate: after a while, there should be something visible. The shrub can be seen, the risen dough can be seen. Others often notice our growth before we do, that's why we need to encourage one another. And where the soil is cluttered with stones, thorns, or brambles (2 Corinthians 13:5), we must dare to clear it.

Key Takeaways

• The kingdom of God always starts small, this is intentional on God's part, not a flaw in strategy.
• The Gospel is dynamite (the Greek word in Romans 1:16 gave us the word "dynamite"): it has transformed world history, it can transform your family, your work, your neighborhood.
• The kingdom does not progress around you if it does not first progress within you.
• Patience and effort go together: the opposite of grace is not effort, it is merit.
• Your spiritual growth is never for you alone, it always nourishes others, just as a loaf made from about twenty kilograms of flour fed several households.

Personal Application

1. Where do you need more patience in your walk with God? Where are you demanding an immediate result from God when he still wants to teach you something?
2. What spiritual effort is God inviting you to start, resume, or persevere in because you're starting to feel tired? Prayer, reading the Word, fasting, church life, a small group?
3. When did you last share the Gospel, wondering if it was even worth it? How does the parable of the mustard seed change the way you sow?
4. Step back and look at the wall, not just today's brick: what has God changed in you over the past three years? Where has the Spirit clearly been at work?
5. Who could you encourage this week by telling them specifically what you see growing in them, a brother, a sister, your spouse, one of your children?

Verses Cited

• Matthew 13:31-33 · The parables of the mustard seed and the yeast
• Romans 1:16 · The Gospel is the power of God
• Revelation 7:9-10 · A great multitude from every nation before the throne
• 1 Timothy 3:6 · A leader must not be a new convert
• 2 Corinthians 13:5 · Examine yourselves to see whether you are in the faith

Further reading

• What to Post on Your Church's Social Media
• What Does Repentance Mean in the Bible?
• What Is Christian Fellowship?

Frequently Asked Questions

Why does Jesus compare the kingdom of God to a mustard seed?

Because the mustard seed was, in the 1st century, the smallest cultivated seed known to his audience. In Palestine, however, a mustard plant could reach up to 4 meters in height, enough for birds to nest in its branches. Jesus deliberately creates a striking contrast between the insignificant beginning and the glorious outcome of the kingdom. In doing so, he encourages his disciples not to despise the modest beginnings of the Gospel.

Does the parable of the yeast have a negative meaning?

In part of the New Testament, yeast symbolizes the corrupting influence of sin or hypocrisy. But here, in Matthew 13:33, Jesus uses it positively: the yeast is the kingdom quietly working through the whole batch of dough until it all rises. About twenty kilograms of flour was the amount prepared to feed several people, Jesus highlights the scale of the effect coming from a tiny ingredient.

What should you do when you feel like you're not growing spiritually?

First, remember that growth is slow: a seed does not become a tree all at once, and you notice almost nothing day to day. Then, step back and look at "the wall," not just today's "brick", has God changed something in you over recent years? Finally, surround yourself with others: they often see our growth before we do. And if truly nothing is moving, it's time to check the watering (prayer, the Word, church life), rather than waiting for motivation to strike.