"It is only by living completely in this world that one learns to have faith. One must completely abandon any attempt to make something of oneself, whether it be a saint, or a converted sinner, or a churchman (a so-called priestly type!), a righteous man or an unrighteous one, a sick man or a healthy one. By this-worldliness I mean living unreservedly in life's duties, problems, successes and failures, experiences and perplexities. In so doing we throw ourselves completely into the arms of God, taking seriously, not our own sufferings, but those of God in the world. That, I think, is faith; that is metanoia; and that is how one becomes a man and a Christian (cf. Jer. 45!). How can success make us arrogant, or failure lead us astray, when we share in God's sufferings through a life of this kind?"
Dietrich Bonhoeffer, Letter to Bethge, July 1944