But the parables didn’t do the work–it put the listener’s imagination to work. Parables aren’t illustrations that make things easier; they make things harder by requiring the exercise of our imaginations, which if we aren’t careful becomes the exercise of our faith.

Parables subversively slip past our defenses. Once they’re inside the citadel of self, we might expect a change of method, a sudden brandishing of bayonets resulting in a palace coup. But it doesn’t happen. Our integrity is honored and preserved. God does not impose his reality from without; he grows flowers and fruit from within. God’s truth is not an alien invasion but a loving courtship in which the details of our common lives are treated as seeds in our conception, growth, and maturity in the kingdom. Parables trust our imaginations,  which is to say, our faith. They don’t herd us paternalistically into a classroom where we get things explained and diagrammed. They don’t bully us into regiments where we find ourselves marching in a moral goose step. (Eugene Peterson )