Jesus said, “The kingdom of heaven is like yeast that a woman took and mixed with three measures of flour until the whole mass began to rise.”
That is a favorite parable for people who would prefer the quiet life of a convent or monastery, but who are forced to fight their way in the business world. Jesus asks them to see all the people they work with as measures of flour that need yeast to raise them up, to make their lives meaningful.
In the years I was teaching high school I every day looked forward to my free period when I could goof off in the teachers’ lounge, but I often met with teachers who redirected me. They were happily at work preparing classes and writing reports to help troubled student straighten out. They were the yeast who raised me up.