The Kingdom: Mustard Seed and Leaven (Luke 13:18-21)

What is the Kingdom of God? What does it look like? How does it work in this “already arrived, not yet fully here” time?

Here in this “rejection” section of the Lucan account, Jesus compares the Kingdom to a mustard seed as well as some yeast. Two things can be seen in these metaphors.

First, the Kingdom is small, gradual, and unnoticed. The mustard seed and yeast are both small, seemingly insignificant, and overlooked. People in Jesus’s day were expecting a grand, overwhelming, spectacular invasion of the Kingdom. God thwarted their expectations. The Kingdom and the Messiah entered subtly into creation. A baby born to poor refugees, not to royalty. A wandering teacher, not a conquering warrior. It may be hard to grasp this reality today, when the Kingdom has grown to represent the largest faith on the planet. Even in that, however, it is not a worldly force—not the true Christianity.

Second, though, the Kingdom is pervasive and unstoppable. From small beginnings, the Kingdom will continue to grow and change the world until Jesus returns. Again, Jesus’s metaphors reflect two ideas about the Kingdom.

First, the Kingdom grows into a large, powerful, influential force for good, in the way that the small seed grows into a plant that birds can nest in. Despite the way that the church has become a human institution, it is also a spiritual institution with the ability to affect good change in the world. It helps the poor and needy, it cares for the widow and the orphan. It has brought down slavery and liberated women. At the same time, like the leaven, it permeates society. The church is an institutional-level force in society, but it is also a group of people in every level of that society. Individually, followers of Jesus impact their world.

The Kingdom changes the world collectively and individually.