True Christianity—as Mr. Bonhoeffer's own example demonstrates—is not a Sunday morning visit to a pew. It's a reorientation of our entire lives in the direction of God. When Jesus bids a follower to take up his or her cross and follow, it is about a way of life—and death—for every faithful Christian. We live to God, and we die to the things of the world—the same dichotomy that is becoming familiar from Augustine's City of God.
The last thing some of us want to hear is that being a faithful Christian is going to cost us something—part of our lives, part of our treasure, part of our freedom.
And yet, that's exactly what it does. Faithful citizenship requires, as Martin Luther King, Jr., said on the last night of his life, a "dangerous unselfishness."
It requires that we be our brothers'—and sisters'—keepers, however much we might wish it didn't.