Another parable He spoke to them: “The kingdom of heaven is like leaven, which a woman took and hid in three measures of meal till it was all leavened.” — Matthew 13:33, NKJV.
Although leaven or yeast is often a symbol of evil (see Matthew 16:11), here Jesus compares the kingdom of heaven to the pervasive nature of leaven and its ability to affect the whole meal. The nature of yeast is to grow and to change whatever it contacts. In like manner, the kingdom of heaven has the ability to permeate the whole world and change the hearts and lives of people who come into it. Jesus’ concerns extended beyond Israel to the whole world.