In the Gospel Reading, Jesus says that the kingdom of God is like a mustard seed. When it is sown in the ground, it is the smallest of all the seeds; but it can grow to become the largest of plants.
So, apparently, the kingdom of God can be very small, or it can change its size and become very, very big.
How does this make sense? Why wouldn’t the kingdom of God always be the same size, the size it has in heaven, for example, whatever size that is?
To see the answer, you have to recognize that the kingdom of God isn’t a peculiar kind of country. God’s kingdom isn’t a place at all. It’s a condition, the condition of God’s ruling as king.
But, we might think, even so, God’s kingdom can’t shift sizes. God’s rule is always the same size: it’s everywhere.
And yet this can’t be completely right. What is ruled by a king is governed by the will of the king. But how much of the world fulfills God’s will? How much of God’s will does any of us fulfill? Everything is subject to the will of God the King, for sure, but not everything fulfills God’s will.
So this is the way in which God’s kingdom can change size. When a person does what is against God’s will, to that extent the will of God is not fulfilled in him. And so, to that same extent, the kingdom of God is small in him . On the other hand, the more a person fulfills God’s will in his life, the greater the kingdom of God in him is.
This is one way we can understand Christ’s parable of the mustard seed, then. When a person first opens himself up to receive God as Lord, the Lord rules very little of him. And so the kingdom of God is like the littlest seed in the ground of his heart. But if only he lets that seed grow in him, if only he doesn’t give up on himself as fruitless, that littlest seed of God’s kingdom will grow and grow in him till it becomes like a great tree in him.
Even a mustard seed’s worth of the kingdom of God within you is enough for hope.