Jesus and the kingdom

“The Kingdom of God is not an ideal which realizes itself in human history; we cannot speak of its founding, its building, its completion; we can only say that it draws near, it comes, it appears.... Even if the parables of the mustard-seed and the leaven really applied originally to the Kingdom of God, they were certainly not intended to denote the ‘natural’ growth of the Kingdom, but were meant to show how inescapable will be its coming.”

—Rudolf Bultmann, Jesus and the Word (London: Scribner, 1958), p. 35.