Matthew 13:33 He told them another parable. “The kingdom of heaven is like leaven that a woman took and hid in three measures of flour, till it was all leavened.”
Luke 13:20-21 20 And again he said, “To what shall I compare the kingdom of God? It is like leaven that a woman took and hid in three measures of flour, until it was all leavened.”
In the Old Testament, leaven was a substance like yeast that causes fermentation and expansion or rising of dough. It was used to create an altering or transforming effect. Leaven is applied to a substance which is very small in number, but with time spreads the substance out. Metaphorically the word “leaven” was used for how it infected people, whether positive or negative.
Positively, in Matthew 13 and Luke 13, we see Jesus’ Kingdom being compared to that of leaven. According to BlueLetterBible, this is like saying that “the saving power of the gospel, which from a small beginning will gradually pervade and transform the whole human race.”
Negatively, leaven (which is like “bread to your soul” – Mark 8:14-21) represents the practice of moral corruption that gradually infects others. For example, the leaven of the Pharisees, Sadducees and King Herod was that of corruptive teachings, hypocrisy, and dissimulation, which means concealing the truth.
But the kingdom of heaven, which encompasses all things that direct us to eternal salvation in Jesus Christ, is similar to yeast inside of a cake. Think about the times where you were in the kitchen and you stared at the ingredients and the recipe for a dessert. You may have wondered why you need such an itsy bitsy amount of baking powder. It is to make the bread rise and appear plump.
This is the same with the Gospel or the Good News. When you first heard about it, I’m sure you did not accept Christ after the evangelist spoke to you. It took you some time – you read, researched, went to church and became familiar with the Body – and finally you understood what Jesus was talking about. That is why the kingdom of God is like leaven. What may seem to be of small significance is rather extreme and pervading, essential for one’s life after death. The idea and reality of the Gospel grows and grows on an individual.
So, in saying this, ponder on how your thoughts were before knowing Christ, and after. If you really reflect on it, you will understand that you have been punctured with grace, and a tiny amount of leaven has transformed your life.