Leaven

In the Bible, leaven is often used to represent things that are bad or unrighteous. Just like the Chinese proverb “do not fail to do good because it is small, and do not do evil because it is small,” the saying that “a little leaven leavens the whole lump” (Galatians 5:9) was a common proverb in Jewish society. It illustrates the influence that something small can have on morality and spiritual life.

At that time, the Israelites did not need to buy leaven. They would simply save a piece of fermented dough from the bread they baked each day to use as leaven for the next batch. Every year, before the Passover, each household would clear out their entire pantry, so no moldy bread was left in the house. On a physical level, this meant clearing out all moldy items; on a spiritual level, it symbolized removing all moldy, fermented things from one’s heart.

The sin in our lives is like leaven. If it is not completely removed, it leaves room for Satan to work. Even a small amount can leaven the whole lump, corrupting our spiritual life and the church.

The Bible records:

[Exodus 12:15] Seven days you shall eat unleavened bread. On the first day you shall remove leaven out of your houses, for if anyone eats what is leavened, from the first day until the seventh day, that person shall be cut off from Israel.

[Exodus 23:18] You shall not offer the blood of my sacrifice with anything leavened, or let the fat of my feast remain until the morning.

[Matthew 16:6, 12] And Jesus said to them, “Watch and beware of the leaven of the Pharisees and Sadducees.” Then they understood that he did not tell them to beware of the leaven of bread, but of the teaching of the Pharisees and Sadducees.

[1 Corinthians 5:6-8] Your boasting is not good. Do you not know that a little leaven leavens the whole lump? Cleanse out the old leaven that you may be a new lump, as you really are unleavened. For Christ, our Passover lamb, has been sacrificed. Let us therefore celebrate the festival, not with the old leaven, the leaven of malice and evil, but with the unleavened bread of sincerity and truth.