This is not to be taken as a philosophy of life or a moral law: it is the gospel of
Jesus Christ, and only so can it be understood. Only those who follow him and
know him can receive this word as a promise of the love of his Father and as a
deliverance from the thraldom of material things. It is not care that frees the
disciples from care, but their faith in Jesus Christ. Only they know that we
cannot be anxious. The coming day, even the coming hour, are placed beyond
our control. It is senseless to pretend that we can make provision because we
cannot alter the circumstances of this world. Only God can take care, for it is he
who rules the world. Since we cannot take care, since we are so completely
powerless, we ought not to do it either. If we do, we are dethroning God and
presuming to rule the world ourselves.
                                                      Dietrich Bonhoeffer, The Cost of Discipleship
                                                        (New York: Simon & Schuster, pp. 178-179)