Luke 13:20&21 “Again he asked, ‘What shall I compare the kingdom of God to? It is like yeast that a woman took and mixed into a large amount of flour until it worked all through the dough.”

Children! Jesus is talking to us about yeast. Mummy can buy a packet of dry yeast in the supermarket. Perhaps she has decided to bake some bread for the church’s Fellowship Lunch. Maybe Daddy has given her an unrequested and unwanted bread-making machine for her birthday. She would have preferred perfume or a blouse but she has to try out the bread-maker. So she brings home the packet of yeast, cuts it open and she pours the contents into a large mixing bowl. When you take a peep at the yeast it doesn’t look interesting or impressive at all. It is what we call dry yeast, that is, the yeast is ‘sleeping.’ Now Mummy is going to wake it up. First she puts in a teaspoon of sugar, and then she pours a quarter of a cup of warm water over the sugar and yeast. What is she doing? She is waking up the yeast. When she adds the liquids, such as water or milk to the recipe, then the yeast begins to wake up. Would you continue to sleep if your sister poured a quarter of a cup of warm water over you? Then nothing much happens for ten minutes, and then Mummy says, “Come and see what is happening,” and you look into the bowl. What do you see? Nothing? Look again. Bubbles are starting to appear; they are coming to the surface. The yeast is waking up from its sleep. It is getting active. More and more bubbles are appearing. The yeast is growing. It is eating the sugar that Mummy put in the bowl. The bubbles that the yeast creates after eating sugar are actually bubbles of carbon dioxide, and the more the yeast continues to eat the sugar the more of this gas is made, carbon dioxide. It is just like you. Every time you breathe out you are breathing carbon dioxide. In fact you’ve been singing these hymns by carbon dioxide. It’s by making this gas that the yeast causes the flour and water to expand and it become fluffy. So the bread rises and grows in the oven or in the bread-maker. The yeast is responsible for doing that.

The Lord Jesus has been talking about the tiny mustard seed, and what a great tree comes from it. Now he speaks to us about yeast. Is yeast small? Is it small? You’d better believe it! The typical yeast cell is approximately equal in size to a human red blood cell. Infinitesimally small; it takes about 30 billion yeast cells to make a gram of baker’s yeast. So the repeated lesson of Jesus is that the kingdom of God is like something alive but initially it is very, very small. In Jesus’ time every mother knew about yeast. In fact 2,000 years before Jesus, down south in Egypt every mother knew about bread with yeast or bread without yeast – unleavened bread was eaten in north Africa at the Passover feast. Archaeologists have discovered the remains of bread with yeast in Egyptian tombs – 4,000 years old! It was Louis Pasteur in 1875 who proved that yeast was a living organism, and that the bubbling and rising is a fermentation process. The yeast actually consumes oxygen and it exhales carbon dioxide, just like us. So what is Jesus teaching?


The Christian Union at the University meets on a Friday night and it numbers about a hundred people. It seems strong but there could be 8,500 students in the University and so there are 8,400 students not coming to the Christian Union. I believe that the C.U. is absolutely right in every claim it makes, and yet the reality is this, that merely one per cent of the students at the university believe this, and this is a typical figure for students’ interest in Christianity in every university and college in the United Kingdom. That number in Aberystwyth on a Friday night is in fact a greater number than many colleges, certainly a larger percentage than you’d find in any European university, but still it is very small. Christians are in a minority in every hall of residence, in every department both arts and sciences, on the sports programmes, in every tutorial group, amongst the undergraduates and the graduates. The question this raises is this, that if Christians alone have the truth why are the vast majority unpersuaded? One reason is that we love ourselves and choose what we are comfiest with, and so we are biased against a message that tells them we need to be converted, that we are under the wrath of God and should repent and seek God’s mercy. But here the Lord Jesus is giving another answer in these two parables. In every generation, as the kingdom of God spreads around the world, he tells us that the kingdom of God always begins small like a mustard seed and like yeast. So often it starts with one person in a family, in a neighbourhood, sometimes in a church. One man travels to a community with a Bible and begins to teach the people the word of God. That is how it is.

So our Lord is saying these things for our encouragement, that the sparsity of the numbers of those in the kingdom of God might not seem an abnormality. Remember how the disciples of Jesus Christ are called to be the salt of the earth. You sprinkle a few grains of salt on your chips not half a pound! We know that just one per cent of salt can prevent a 99 percent mass from putrefying and it can preserve the meat or the fish. We are also called to be the light of the world; one small light bulb can drive the darkness out of a whole room. So don’t lose heart; don’t think you are having no impact. It is the devil who either drives you to despair or to pride. Don’t measure the growth or success of the kingdom solely by statistics or visible excitements. Jesus said to the Pharisees, “The kingdom of God doesn’t come with observation; nor will they say ‘See here!’ or ‘See there!’” (Lk 17:20-21). That is the Muslim error, or the Mormon mistake, or the mega-church misconception when they measure God’s blessing by bigness and spectacle and noise. “We’ve got it!” The criteria for God’s kingdom is this, Jesus tells us, “Indeed, the kingdom of God is within you” (Lk. 17:21). What is within you? The yeast. What are its marks? The blessedness of being poor in spirit, the blessedness of mourning for our sin, the blessedness of a meek and humble spirit, the blessedness of being pure in heart, the blessedness of hungering and thirsting for righteousness, the blessedness of being a peacemaker. You can’t see those graces; they’re not in your face; the world doesn’t cry, “Wow! See here! See there! We’ve got it!” because they are within your heart and soul and impacting your lifestyle.

So a hundred students meeting together and living a Christ-like wise and loving life in a university is indeed just right to be the salt of our college. The testimony is there on notice boards, and in your meetings, and in ‘Tea and Toast’ evangelism to students who are inclined to drink too much and party too long. Wherever the mustard seed is being scattered, then the word of life will produce fruit. Don’t lose heart. Go on being steadfast, unmovable, always abounding in the work of the Lord, knowing that your labour is not in vain in the Lord. The yeast is tiny to begin with, but it is going to affect the whole loaf of bread. It is going to make something delicious and satisfying, not a flat life dependent on addictions and non-stop entertainment, but new life all through something very small.

I love to read the brief testimony of how a friend of mine Mike Phelan became a Christian. He had never been to church and he had no interest in Christianity when he entered a Charity Shop one day, and the heading of a second-hand book caught his eye; Good News for Modern Man. He picked it up and thumbed through it and he bought it for a few pence. This was his response; “When I first began to read the Scriptures, it was in total isolation from any Jewish or Christian individual or organisation. I didn’t even know that the book I had purchased, entitled Good News For Modern Man, was a New Testament. As I read its pages, I was drawn more and more deeply into the heart of its teaching until I reached a definite point where an event of recognition occurred. Without the aid of any other human, immediately and comprehensively, I was granted the realisation that what I was reading was absolutely and eternally True. The impact this recognition made upon me was life-changing, and brought a feeling of joy combined with wonder and awe. For me, there could be no going back: from that moment on, I knew I was reading words that forever were true, and must be lived by, and, if need be, died for” (M.W.J. Phelan, The Inspiration of the Pentateuch, Twoedged Sword Publications, 2005, p.17). By the Book living yeast from heaven came into his life and immediately it began, as it were, fermenting and bubbling away, changing his life for good. So my first point is that the kingdom of God begins very small.


There are a couple of Old Testament verses which you often find quoted by our fathers in the faith and I love them. Jehovah is speaking to his people as they are about to enter the Promised Land and he tells them what is his strategy for their victory over the pagan nations who live there already, shameless, profane people who practiced child sacrifice as they worshipped the god Moloch. God could have sent forth one angel and commanded him to exterminate the lot in a moment, and the the people would simply walk in and take over. But the Lord says, “But I will not drive them out in a single year, because the land would become desolate and the wild animals too numerous for you. Little by little I will drive them out before you, until you have increased enough to take possession of the land” (Ex. 23:29&30). “Little by little” he says, “as you increase in strength and they get weaker. That will be the best way.” “Little by little,” our fathers would say as they spoke of the growth of a church and the change in Christians. It has been the story of my years of ministry in this congregation

That’s the simple picture from the Old Testament of slow steady change. Now let me give you the buzz words. They are useful; they are this phrase, ‘progressive sanctification.’ Let me just expand that into an important statement. Are you ready? “Progressive sanctification is effectual in every true Christian.” You can understand that; it’s very simple though the buzz words are a mixed blessing. Without them I am simply saying this, that God sticks at his work. He is going on in every Christian’s life to achieve his purpose for us all. He is changing all real Christians so that when they finally see him they will be like Christ. I am confident that that is what God is doing now in every one of the elect because God himself declares this very clearly. He says it, for example, in the letter to the Philippians and the first chapter and verse six; “being confident of this, that he who began a good work in you will carry it on to completion until the day of Christ Jesus.” If God really begins to create a trust in the Lord Jesus Christ in your heart, a saving dependence upon him, a belief in the promises of the gospel, and repentance about your sins then he has set a divine momentum into motion, an irresistible and unstoppable force. He will keep those wheels turning in your life; the process is not going to break down half way through in any true believer. God won’t stop; he won’t give up on you even though you are a hard nut to change. He who begins will carry it on to completion to the very end, the day of Christ Jesus – that is, at the second coming. The divine yeast will never stop lifting you up; it will still be operating away in your hearts, the same gracious saving and sanctifying divine power that had started maybe hundreds if not thousands of years earlier when you first were brought into the orbit of the gospel. A tiny bit of heavenly yeast was once mixed into the heart of Abraham 4,000 year ago, but not until the day of Christ will the process be completed. God began the good work in him, and in many of you and me, and little by little, with many falls and disappointments every week and every year, the work goes on.

We have often cried to God to speed up the process: “O Lord make a miracle out of this mess today!” And there never will be any shortage of books and speakers with the theology of the short-cut to heaven and holiness. “They’ve got the formula! They’ve got the hidden knowledge! Just take it on board and your churches and lives will be changed overnight.” The fact is that God has not promised to sanctify and mature Christians immediately. He does, of course, immediately deliver us from the guilt of all our past sins. He does immediately declare us to be righteous. He does immediately give us a new heart and make us a new creation. He does immediately adopt us into his family. He does immediately join us to Jesus Christ, putting us in him. He does immediately remove the lordship of sin from our lives and become our Sovereign Protector. That is true for every single Christian. We prayed something like, “Make me a real Christian,” and God’s answer was exceeding abundantly above all that we ask or think. But God does not instantly make us Christ-like. He does not give us total holiness. He does not fill every cell in our brains with divine wisdom. He does not remove every particle of remaining sin from our lives. He does not put us in a place where for the rest of our lives we are never troubled by a single temptation from Satan. That is a fantasy world. Little by little the yeast grows in our lives; sanctification – making us holy – is progressive. In our early months and years as Christians God keeps from us how powerful remaining sin can be. That knowledge – the discovery of what we are carrying around in the dark caverns of our souls – would overwhelm us with despair, but as we make some progress in loving, and in humility, and knowing Jesus Christ in his threefold offices and as God and man, so God lifts up the covering a little, and allows us a peep at the power of indwelling sin. Then we know that the only way we are going to get to heaven is by grace – that is omnipotence acting to redeem us – and we flee to Christ again; “Thou must save and Thou alone.”

It is a gradual growth; it is progressive sanctification; little by little the yeast of grace begins to give a taste of the life of heaven to our lives. We will always be the last to recognize it in ourselves. We will just see how foolish and immature we are, but so thankful for the pity of the Lord to us. He is giving us more victories over temptations; more trust in the Saviour; more knowledge of his Word, more thoughtfulness towards others, more evangelistic concern. We are never going to be perfected while we are in the body; we can never claim we have arrived; we will advance three steps and then fall back two. We often fall through the same familiar sins of thought and word and deed, but we keep picking ourselves up. There was a man who once was a member of this congregation, and I’d ask him how he was, “Pressing on,” he would say. He was quoting Philippians chapter three and verse four; Paul said he was pressing on. It is a great response, we are pressing on towards the mark of the prize of the high calling of God in Christ Jesus. The heavenly yeast is going to work; the Mountie gets his man, they say, and God achieves his goal for me and you. At the moment of our deaths our souls will be made perfect in holiness and immediately pass into the presence of God.

Let me apply the parable of the yeast in this way. Perhaps you have professed to be a Christian for a few years and you often think that you are not like other Christians who seem much stronger and full of faith than you, that if they knew what you were really like they might even move away from you in the pews, that your life as a Christian is one of failure and hypocrisy. You fail to control your tongue; you fail to control your imagination; you fail to control your laptop; you fail in daily devotions. Sin so easily besets you. I am saying to you that such times of sadness and doubt every Christian passes through. Every believer here has felt like that at one time or another. It is part of growing up and becoming mature and turning your focus away from yourself and fixing it on Jesus Christ. You are simply discovering the reality of what you first said when you told the Lord that you were a sinner, and you needed to be saved. Then you knew it in your mind, and by the testimony of your conscience, but now you have been a Christian for some years your affections seem to be ganging up together against you – discouragement, fear, exasperation, pain, despair, weariness – and the devil is also firing his fiery darts at you and saying to you, “You can’t be a Christian to be living like this.” That is a perfectly understandable response that every single Christian feels often. That is why you need the mercy of God every single day. I am saying to you that this is an evidence that the yeast of grace is really in your life. Non-Christians in Aberystwyth don’t feel like that at all. Only Christians feel that they are not the sort of people they should be. Take heart! You are far more wicked than you realise! Take heart! You are loved by God far more than you appreciate or deserve. God has begun a good work in you; the yeast is at work, and he will finish his plans for you. He has made up his mind.

I can look back at my life and judge that I have been a total failure; I have failed as a husband, as a father, as a pastor, as a preacher, as a friend, as a counsellor, and I can look back and dismiss all my life as one massive failure, or I can do something else. I can plead his promise that he who has begun the good work in my life will go on performing it until the day of Christ. God is not giving up on me. “O Love that will not let me go please don’t take the yeast away. Don’t stop the yeast from working. How I need you to permeate every part of my life, and change me inwardly and steadily as you have promised.” I must walk by faith not by faith. Where my sin abounds God’s grace far more abounds. The norm for every Christian is gradual growth.


i] Humility. Every virtue we possess and every victory won and every thought of holiness is due to the heavenly yeast. If there is some growth in understanding, if there is some delight in Christian fellowship, some joy in hearing the gospel preached not in word only but in power and with the Holy Spirit and with much assurance, if I enjoy the company of Christians listening to them talk of the things of God then it is all because of the yeast. If I believe that I am awake to the things of Christ whereas once I was sleeping, then it is because of the yeast. If I say words like this to other people, “Please be patient; God is not finished with me yet” then it’s because of the yeast I think like that. If I believe that God will never allow a trial to come into my life where he will fail to keep me, then it is because of the yeast. God has done it. My calling is to work out my salvation with fear and trembling – that is to take it very seriously – knowing day by day that God is working in me by the yeast, to will and to do of his good pleasure. I am saying that this teaching of our Lord that the kingdom of God is like yeast silently and mysteriously working away in my heart and soul makes me humble. “Please don’t stop for a moment,” I cry to God.

When I see many true churches in Europe struggling numerically and barely surviving I dare not look down my nose at them. They are sister congregations; they are in the family; how are they doing? I can pray for them. “Please let the yeast work powerfully in their midst!” I can write letters to the pastor or officers of friends. God can change things. I was sent this week a review of a 540 page biography of a German preacher named Johan Christoph Blumhardt. When he was 36 in 1841 he was pastoring a congregation in a little town named Mottlingen. Nothing much was happening until he helped deliver a woman from apparently locked-in wickedness and depression. The yeast powerfully worked in her life. The effect of her transformation impacted the whole church and then the community and even further afield. An unprecedented movement of repentance and a turning to God took place. Stolen property was returned, broken marriages were restored, enemies were reconciled. Drunkards were delivered, and the entire village was changed. Scores of people traveled to be at the services, and Blumhardt pointed them all to Jesus Christ. The manse could not accommodate the number of people who moved there. He moved to a larger house, a complex of buildings, and there desperate people of all stripes, men and women burdened with mental, emotional, physical and spiritual problems found deliverance and trust in Jesus Christ. I am sure that when I get the book I will not agree with everything Blumhardt believed and did, but I see there the power of the heavenly yeast to change churches and communities and I long that such a work were seen in one place in Wales today. God alone can do it; and God does it by the yeast he has given to each one of us. I am saying that the doctrine of the kingdom of God being like yeast teaches us humility.

ii] Hope. This is our Father’s world. He has not discarded it. John 3:16 is still true. This cosmos is loved by God; he created it; he sent his Son to it; he is building a church in it; he is hearing the prayers that rise from it moment by moment, and answering them. What does this tell us about the Christian view of the future? It makes us optimistic, even on a material level. The proportion of the world population living in poverty has fallen from 52 per cent in 1981 to 26 per cent in 2005. The average Botswanan now earns more, in real terms, than was earned by the average Finn in 1955. Life expectancy is increasing by about three months per year, and infant mortality is now about a third of the rate – across this earth – than it was in the 1950s The world agricultural system is now producing 2,700 calories per person per day – 17 per cent more than 30 years ago. There are huge reserves of natural gas to provide the world’s energy needs. The world wide web is bringing information to people everywhere at the touch of a switch.

But we are more interested in spiritual and gospel matters. There are millions and millions of Christians in the world today, more than there has ever been in all human history. In the most remote corners of the world you will find congregations of the Lord Jesus Christ, in Siberia, in the interior of Papua New Guinea, in the north of Kenya amongst the Rendille people in semi-desert conditions, all over China, in Japan this very day among the firemen trying to keep nuclear reactors from over heating there are Christians. In Wall Street and Hollywood, in Soho and Moscow you will meet Christians. In those places and a million more you will find congregations of God’s people. They are not ghettoes of one race from the middle east or Pakistan. They are people from every nation in the world. There seems to me to be no likelihood whatsoever that this work is ever going to end, but rather increase. If there is a temporary decline in Europe then it flourishes in North and South America, in China and Korea. While God continues to give the yeast to every one of his people then there will be growth and there will be churches everywhere.

Of course there will much opposition and many disappointments. We are battling with the forces of hell. Our fight is with principalities and powers, with the world and remaining sin. The parable of the sower tells us that some seed quickly springs up and just as quickly it dies. Other seed is choked by the cares of this world, but other seed produces 100-fold. God has begun a good work in that seed and he is not going to stop his work. So let me use a buzz word again, my eschatology, my doctrine of the future and the end times, is utterly optimistic. If you should ask me whether Christ or the devil is going to prevail in history – in the time before us, prior to the Lord’s return – then I’m assured of the triumph of Christ. The Bible says that Satan and the Beast of Revelation have already been defeated. Christ has made a show of them openly by his cross. The devil is in chains and if he should attempt to creep up on one of those in whom God has put the yeast to destroy that little Christian girl then Christ will yank the chain. He will keep us from Satan. He says, “I will build my church and the gates of hell will not prevail against it.”

Christ is not less powerful now than he was when he walked this earth. It is now that he has all power in heaven and on earth. He once claimed, “If I cast out devils by the Spirit of God, then the kingdom of God is come unto you” (Mat. 12:28). The kingdom of God is already here, but it has yet to grow to its fullness. In history, God’s kingdom has been advancing little by little. That kingdom is a grain of mustard seed, which a man took, and sowed in his field until it grew into a great tree (Mat. 13:31). That kingdom is like yeast, which a woman took, and hid in three measures of meal, until the whole was leavened (Matt. 13:33). The kingdom of God has been progressing and growing and today it has spread into the whole world.

We are people of hope; we have a theology that tells us it is impossible for us to think of a Christ who is wringing his hands in horror at the end of the world finding hardly one man preaching the gospel. Theology has consequences. We believe that Christ is going to triumph in history, and when all things are put under his feet then the last enemy, death, will be destroyed. “For he must reign, till he hath put all enemies under his feet. The last enemy that shall be destroyed is death” (1 Cor. 15:25,26). We are told that “the kingdoms of this world are become the kingdoms of our Lord and of his Christ” (Rev. 11:15).

What we believe does have consequences. John Bunyan said, “Hope is never ill when faith is well.” If we believe that Satan is already bound according to Revelation 20 and verse two, and Christ is seated on the throne of heaven, what hope we have. Then we ought to work with all our might and main for the increase of the kingdom of God. None of our labour in the Lord is in vain. Of course, Satan is not bound in every respect. We don’t believe that. He is going about seeking whom he may devour. Christ has bound Satan for a well-defined purpose: “to keep him from deceiving the nations any more” (Rev. 20:3b). Once we in Wales were bound by druidism and our ancestors worshipped trees, mountains, tides, the moon and the sun. Those objects never answered when men spoke to them and sacrificed to them. Poor captive Welshmen! But no longer does Satan bind us. The Son of God has made us free. In the Old Testament only Israel knew the true God, but today the Gospel is preached to all nations. These are millennial days for the gospel to be preached all over the world. The mountain of the Lord is rising in these latter days. What raises mountains? You get this extraordinary answer, yeast from heaven. It causes bread to rise and it causes mountains to rise. We look around us and we see the mountains, the re-emergent, hostile, non-Christian religions, materialism, new, militant, anti-Christian atheism, the ideas of the new age, the cults, sacerdotalism and so on. Mountains of opposition all around us, but here is Mount Zion, the hill of the Lord and it is alive and growing. The yeast is lifting up and up and up.

God has added to your life this yeast. To the ingredients of your life, to your affections, and your desires, and your knowledge, and your zeal this yeast has been added. How are you nourishing that yeast? Are you bringing truth and understanding to that yeast? Are you listening to the word of God each Sunday, sitting under the best preaching you can get? Are you exercising your heart and life spiritually, bringing into action your concerns, and your understanding, and your compassion, and your prayerfulness. Is there that warmth and light that comes from the presence of the Lord and communion with God which makes your spirits rise? Is there that oxygen that comes from the nearness of God? You must labour to encourage the yeast to influence every part of your life. We go back unless we go forward. We go forward only by working and striving. We cannot float upstream.

27th March 2011 GEOFF THOMAS