This is what the kingdom of God is like. A man scatters seed on the ground. Night and day, whether he sleeps or gets up, the seed sprouts and grows, though he does not know how. All by itself the soil produces grain—first the stalk, then the head, then the full kernel in its head. As soon as the grain is ripe, he puts the sickle to it, because the harvest has come.
This parable is a parable of hope. The growth of the kingdom is not the work of individual Christians—or even the Church as a whole—but rather is the work of God Himself. Because of this, the growth of the kingdom is hidden and mysterious. Yet it is also certain, for “night and day, whether he sleeps or gets up, the seed sprouts and grows, though he does not know how.” Though we cannot see God at work in the world to save it, though it seems to grow “all by itself,” we have a certain hope and confidence. The good news itself is latent with power and a will to shine forth, illumining the deep darkness of this world. We are merely observers and participants in its work.