The story being told in the film is not Bonhoeffer’s story. It’s not the Confession Church’s story. Nor is it the story of the German resistance against Hitler. It is a completely fictional story of Hollywood.
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.