“The kingdom of heaven is like yeast that a woman took and mixed into a large amount of flour until it worked all through the dough.” Matthew 13:33
This is the final brief parable that sums up to the crowd the picture given by Jesus of the kingdom of heaven so far. It is also known as the parable of “The Yeast”, and is often understood as the yeast being a picture of the spread of the goodness of God throughout the world, but it is more likely the complete opposite.
Yeast in Scripture is a consistent picture of evil. From the time of the Passover when God brought Israel out of Egypt, bread eaten in celebration of God’s goodness was to be without yeast. Jesus speaks of the “yeast of the Pharisees and Sadducees”, which the disciples understood Him to mean guarding against the teaching of the Pharisees and Sadducees” (Matthew 16:6 & 12). Paul exhorted the Corinthian church, “Your boasting is not good. Don’t you know that a little yeast works through the whole batch of dough? Get rid of the old yeast that you may be a new batch without yeast… not with the yeast of malice and wickedness, but with the bread without yeast, the bread of sincerity and truth” (1 Corinthians 5:6-8).
If yeast is consistently used to depict evil in Scripture, this parable is unlikely to be an exception. It is not that the kingdom of heaven is like yeast, but that the kingdom of heaven is like yeast mixed into a large amount of flour until it works through the dough. It is the whole picture, all of the dough that is likened to the kingdom of heaven. Evil is contagious; righteousness is not. Cleanliness does not spread; dirt does. The yeast permeates to every part of the dough, which is why we are not given hope on earth of perfection in our personal lives or in the corporate life of the church. As long as we live within a fallen environment we are vulnerable to contamination by sin and subject to failure. Only in heaven is there the prospect of being free from the contamination of sin.
This is not to put a pessimistic view of the kingdom of heaven in its expression on earth, but to be utterly realistic as history and contemporary experience have served to confirm. This is the view of the kingdom given to the crowds. It is the perspective from outside the kingdom and is neither attractive nor appealing. It is unlikely to be held up as the ideal of society, and will not draw people in its natural state. There will always be reason to criticize and disregard it, which is how the kingdom of God is seen by the world at large.