But in the spiritual life, the word discipline means "the effort to create some space in which God can act." Discipline means to prevent everything in your life from being filled up. Discipline means that somewhere you're not occupied, and certainly not preoccupied. In the spiritual life, discipline means to create that space in which something can happen to you that you hadn't planed or counted on.

Henri Nouwen. Moving from Solitude to Community to Ministry.