NOTES for Luk 13:18-21
When speaking of the Kingdom, Jesus often compares it to something that at first seems tiny and almost imperceptible, but eventually becomes obvious to everyone precisely because of its size. The Savior frequently speaks of the Kingdom as a seed that needs time to sprout; once it does, it can no longer remain hidden, just as one cannot fail to notice what has grown. This concerns the antinomic nature of the Kingdom. On the one hand, it comes into our fallen world from outside, like a seed the sower casts into the earth. The seed is not born in the soil or produced by it, and the Kingdom likewise does not take shape within our fallen world as an organic part of it: it comes from outside.
Once in the earth, however, the seed does not sprout immediately, and it grows according to laws determined in part by the nature of the soil on which it fell. Once it has entered the earth, it begins to live and develop according to that earth's laws. Yet its own nature still cannot be reduced to the soil alone: the seed is far more than the soil that nourishes it, and its potential far exceeds even that of the most fertile soil on earth. The seed uses the potential of the soil in which it lands, but in doing so completely changes the character of what it uses. This new quality is realized in the plant that develops from the seed.
Without the seed, no soil could acquire such a quality on its own: it does not and cannot contain the life present in the seed, a life realized through the soil's possibilities but absent from the soil as such. In the same way, the seeds of the Kingdom, its power and its breath, entering our fallen world, sprout within it, transforming and renewing it. As with a germinating seed, the changes are not immediately visible, but once the process reaches a certain stage, it becomes almost impossible not to notice them.
Of course, someone determined to do so can ignore even a large, spreading tree, turning away and pretending it does not exist. But that is unwillingness to see, not the object's invisibility. Meanwhile, the Kingdom does not become the fallen world or dissolve into it. It merely uses what can be used for its own growth and rootedness within the world, transforming it accordingly. It is no surprise that at the end of time the world is completely transfigured, losing only what cannot be transfigured because of its own condition. This is how God acts, desiring to save everything and everyone in the world that can be saved.