A little leaven leaveneth the whole lump. Galatians 5:9
Many years ago, we decided to try our hand at making sourdough bread. The first step in that process is to make a starter, unless you obtain a starter from someone else who makes sourdough bread. The process was very simple; we mixed some flour and water, and left the mixture sitting in a bowl on the kitchen counter. It took only a few days, and a bit of added flour each day, for the mixture to start to ‘work’. One night it ‘worked’ so well that it overflowed the bowl. Why did it bubble and grow? We didn’t add any yeast to it. The experts tell us that wild yeast is everywhere, in the air, even in the flour. And without any prompting by us, that wild yeast begins to do its work wherever it finds a medium. It’s just like bad doctrine that is allowed to make its way in among the Lord’s people.
Our text is part of a discourse by Paul as he deals with a problem in the Assembly in Galatia. Someone has come in among the Christians with teaching that they need to observe certain parts of the law in order to be saved. Paul likens this false doctrine to leaven, which is always a symbol in the Bible of sin and corruption. The purpose of leaven is to make bread rise. That is a picture of pride, the lifting up of the flesh. The false doctrine of legalism leads to pride, because those who follow that doctrine take pride in their own works. And we know that our salvation is not of works, lest any man should boast (Ephesians 2:9). And just like leaven that spreads itself throughout the dough that it is put into, bad doctrine contaminates everyone who it comes in contact with. That is true of the false doctrine of legalism, and of every other type of false doctrine that comes along. How do we preserve ourselves from the leaven of false doctrine?
For Passover, and the week that followed it, the ancient Israelites were to eat unleavened bread. But if the wild yeast was all around them, how did they prevent their bread from becoming contaminated by it? There were two steps in that process: they mixed the bread up fresh every day, and they kept the dough covered to keep the wild yeast out. When it comes to keeping out the false doctrine from among us, we need to be reading and studying our Bibles afresh every day. The daily application of the Word of God will preserve us and keep out the leaven of sin and error. Just as the Israelites protected the dough, we also need to protect ourselves by avoiding the contaminants of sinful companions and places, by avoiding those things that will allow the world to seep into our souls, whether it be godless music, unwise reading material choices, or activities that rob God of the time and effort that He deserves from us.
It does not take much yeast to leaven a large batch of bread. Nor does it take much sin or error to mess up our lives. We need to be on our guard. -Jim MacIntosh