The real power of his hymn comes from the fact that Bonhoeffer does not offer a rosy picture of life or any of the tropes so typical of cheap piety that tell us that everything is always right, that things happen for a reason, and that we should try to stay positive.
Original Sin: What Does this Mean?
The danger of denying the truth of our common human fallenness and brokenness by original sin is that the denial of this doctrine may also lead us to the denial of Christ as our Savior.
Preaching Saints: On the Communion of Saints and Being Kept in the Faith
While the Holy Spirit does work within us, He always comes to us from the outside, through the external Word and Sacraments.