Jesus is still teaching about the kingdom of God, Luke 13:20 / Matthew 13:33, and in this parable, He shares a lesson from something He saw His mother doing time and time again, Luke 13:21 / Matthew 13:33.
We know bread was made at home in Palestine during this time, and everywhere you went, you would see women making bread. Everybody knew about the little piece of dough, which had been kept over from the previous baking, which was called yeast, and the yeast was basically a piece of fermented dough.
Jesus told a parable here, which would have highly offended those who were listening. We might be thinking, well, what’s the big deal? He’s talking about yeast. Well, to understand why they were offended, we need to enter the mind of the Jews again.
In Jewish thinking, yeast or leaven is almost always connected with an evil influence. The Jews connected fermentation with deterioration and rottenness, and yeast stood for that which was evil, Matthew 16:6 / 1 Corinthians 5:6-8 / Galatians 5:9. Now we can understand why the Jews would struggle with this parable.
They would be thinking, how could the kingdom of God be compared to yeast? How can God’s kingdom be compared with evil? Remember when God spoke to Moses and Aaron about what the Israelites were to do in preparation for the Passover? One of the ceremonies of preparation for the Passover feast was that every scrap of yeast had to be taken out of the house and burned and destroyed, Exodus 12:8-10.
I believe that Jesus chose this illustration of the kingdom deliberately. Imagine if you were a Jew and you were there listening to Jesus, there would be a certain shock in hearing that the kingdom of God is compared to yeast. But that shock would arouse interest and get attention, as an illustration from an unusual and unexpected source always does.
Jesus spoke of yeast in the good sense; He saw how the women use it for a good purpose to make light and wholesome bread. And so when you look at yeast the way Jesus looks at yeast, you can understand that the kingdom of God is like yeast in many ways.
So now that we understand the background to this parable, I would like to share with you three thoughts about this yeast or leaven, as some translations have it.
1. The yeast of Christ works from the inside out.
Those of you who are bakers and make your own bread will know exactly what I’m talking about. When you’re making bread, you know that yeast will do nothing to your mixture unless you mix it through, and that’s because yeast does its work from within. In other words, yeast can do nothing to the dough unless it’s put inside; it has to get right inside the dough to work properly.
Christianity works the same way; the influence that changes a person works within a person’s heart. You can change the external things about your life, but your heart will still be the same. A poverty-stricken nation may receive food and clothing and better housing, but that nation will not really be changed until it’s given something within.
The task of Christianity is to make new men, not new things. It’s not the outward things that are the problem; it’s the human heart that’s the problem, Mark 7:21-22. In other words, once the new people are created, the new world will follow.
A man isn’t converted unless he’s converted within; a person isn’t converted unless their heart is changed. So Christianity is like yeast, it’s not the outside trying to get in, but the inside trying to get out, Proverbs 27:19.
2. There’s real quality in the transforming power of yeast.
Did you know that when yeast is put into the baking meal, it changes the ingredients? It does. What happens is that the dough is turned into a bubbling, seething mass. When Christ and His kingdom are introduced to people, great changes take place. And that’s because Christianity is a disturbing thing; it disturbs people, it upsets people, Acts 16:20-21 / Acts 17:5-8.
But why do they get upset? They get upset because God’s Word exposes their sin, Hebrews 4:12. And sometimes you don’t even have to say a word about God, but because they know you’re a Christian, you’re exposing their darkness, and people don’t like being exposed, John 3:20.
But these are the kind of people that Christ can help because when Christ comes into a person’s heart, that person becomes a new man or woman. Paul says when a person lets the yeast of Christ work in them and through them, they have new thoughts, Colossians 3:1-4.
A Christian starts to think differently about themselves and the world they live in. Paul says that a person who comes into contact with Christ starts to live differently, Colossians 3:5-7. But something else happens to a person when they accept the yeast of Christ.
When the disciples were talking about places of honour, Jesus says that when you become a Christian, your idea of work changes, you get new ambitions of work and service, Matthew 20:25-28.
The yeast of Christ is so powerful that it can take a person like the apostle Paul, who said that he was the worst of all sinners. And how does He do that? Christ does that because He loves us, and He has told us that whoever becomes a Christian is a new creation because the old has gone, 2 Corinthians 5:14-17.
When you allow Christ to influence your life with His words, you will be amazed at the results. Jesus Christ can change someone who is willing to allow God to change them, Galatians 5:22-24. The yeast of Christ is powerful, loved ones, and there’s not a person you have ever met or will ever meet who cannot be changed by the Word of God.
3. The yeast of Christ cannot be contained.
Yeast works contagiously, Luke 13:21 / Matthew 13:33. When yeast gets put into the mixture, it doesn’t stop until it has spread through the whole mixture. And Jesus says that’s exactly what the kingdom of God is like, it spreads like an infection.
When you think about some of Jesus’ first disciples, other people brought them to Him. In other words, Andrew found Peter and Philip found Nathanael, and from then onwards the number of disciples just grew and grew and grew, the early church multiplied by leaps and bounds, John 1:40-45.
When you think about the Lord’s church, it’s very much in the soul-winning business. Where we’re reps for Jesus Christ, and the only way the church can do its business is for every single member to be a soul winner for Christ, too.