The Parables of the Mustard Seed and Leaven

The Parables of the Mustard Seed and Leaven in Luke 13:18-21 describe the growth and spreading influence of the church, but from different approaches. The parable of the mustard seed is about outward growth. Birds from outside fly into and become part of the tree. The parable of the leaven is about inward growth. The leaven works from inside the dough. Leaven makes dough rise from within which pictures the way the gospel changes us inwardly: it changes our hearts and then works its way into our actions.