It's really hard to know how to review such a poignant correspondence fairly or objectively. It's the kind of book where, when you finish it, you are simply overwhelmed, speechless, because the one whose correspondence you have been reading is made speechless by a violent act, executed just months before the end of the Second World War.
Eberhard Bethge, who originally collected and published this material under the title "Widerstand und Erbegung," knew how important and powerful this collection of letters were, but was also understandably humble about publishing a collection in which he himself figures so prominently. So he focused on publishing Bonhoeffer's ethics first, only later issuing this collection. Ever since it was published, it has caused a stir in Bonhoeffer studies, because it forces readers to re-think much of what they think they know of Bonhoeffer, especially through is most popular works like Discipleship (Cost of Discipleship) and Life Together.
Central to this re-appraisal is the concept he is developing of "religionless Christianity." Here's a very important passage:
"A few more words about "religionlessness." You probably remember Bultmann's essay on "demythologizing the New Testament." My opinion of it today would be that he went not "too far," as most people thought, but rather not far enough. It's not only "mythological" concepts like miracles, ascension, and so on (which in principle can't be separated from concepts of God, faith, etc.!) that are problematic, but "religious" concepts as such. You can't separate God from the miracles (as Bultmann thinks); instead, you must be able to interpret and proclaim them both "nonreligiously." Bultmann's approach is still basically liberal (that is, it cuts the gospel short), whereas I'm trying to think theologically. What then does it mean to "interpret religiously"?
It means, in my opinion, to speak metaphysically, on the one hand, and, on the other hand, individualistically. Neither way is appropriate, either for the biblical message or for people today. Hasn't the individualistic question of saving our personal souls almost faded away for most of us? Isn't it our impression that there are really more important things than this question (--perhaps not more important than this matter, but certainly more important than the question!?)? I know it sounds outrageous to say that, but after all, isn't it fundamentally biblical? Does the question of saving one's soul even come up in the Old Testament? Isn't God's righteousness and kingdom on earth the center of everything? And isn't Romans 3:24ff. the culmination of the view that God alone is righteous, rather than an individualistic doctrine of salvation?
What matters is not the beyond but this world, how it is created and preserved, is given laws, reconciled, and renewed. What is beyond this world is meant, in the gospel, to be there for this world--not in the anthropocentric sense of liberal, mystical, pietistic, ethical theology, but in the biblical sense of the creation and the incarnation, crucifixion, and resurrection of Jesus Christ. Barth was the first theologian--to his great and lasting credit--to begin the critique of religion, but he then puts in its place a positivist doctrine of revelation that says, in effect, "like it or lump it." Whether it's the virgin birth, the Trinity, or anything else, all are equally significant and necessary parts of the whole, which must be swallowed whole or not at all.
That's not biblical. There are degrees of cognition and degrees of significance. That means an "arcane discipline" must be reestablished, through which the mysteries of the Christian faith are sheltered against profanation. The positivism of revelation is too easygoing, since in the end it sets up a law of faith and tears up what is--through Christ's becoming flesh!--a gift to us. Now the church stands in the place of religion--that in itself is biblical--but the world is left to its own devices, as it were, to rely on itself. That is the error. At the moment I am thinking about how the concepts of repentance, faith, justification, rebirth, and sanctification should be reinterpreted in a "worldly" way--in the Old Testament sense and in teh sense of John 1:14. I'll write you more about it." (374-375, Dietrich Bonhoeffer Works, volume 8)
Theologians and church leaders will be especially interested in sections of the work such as this, but they will need to be patient. Bonhoeffer does not get around to "doing" such theology until the middle of the correspondence. However, to skip to these sections without reading the whole of the correspondence is problematic, because these passages only make sense in an overall correspondence in which they are situated.
In fact, I can suggest to readers that the only way to truly read this volume is to be prepared to read it lovingly, slowly, and carefully. It takes time, but yields much. It is the overall development that is persuasive and (at times) almost overwhelming. Towards the end, you enter into his experiments with poetry, which make little sense outside of context, even if they also stand alone as poetry does. And the last few letters remind readers of how much wasn't said, or was said sideways. The very fact of his imprisonment pushes these letters into a kind of surreal or postmodern mode that is all the more realistic for being postmodern.
I cannot recommend the whole book highly enough. The critical apparatus is also top-notch, as in all of the Dietrich Bonhoeffer Works. Thank you Fortress Press.