Viewed from a Christian perspective, Christmas in a prison cell can, of course, hardly be considered particularly problematic. Most likely many of those here in this building will celebrate a more meaningful and authentic Christmas than in places where it is celebrated in name only.
That misery, sorrow, poverty, loneliness, helplessness, and guilt mean something quite different in the eyes of God than according to human judgment; that God turns toward the very places from which humans turn away; that Christ was born in a stable because there was no room for him in the inn — a prisoner grasps this better than others, and for him this is truly good news.
And to the extent he believes it, he knows that he has been placed within the Christian community that goes beyond the scope of all spatial and temporal limits, and the prison walls lose their significance. . . .
With great gratitude and love,
Your Dietrich4
Suffering Brings Meaning to Christmas

Ironically, we can miss this meaning of Christmas if our celebration is only wrapped up in comfortable warm fires and the fellowship of friends and family. We can miss the memory of our desperation that required the Son of God to suffer for us. We can miss the personal desperation met in the manger. And we can miss out on the fellowship of his sufferings.
As we have recently explored, Christmas and suffering are deeply interwoven themes in Scripture. Personal suffering brings deeper meaning to Christmas. And in a season of suffering, the child of God discovers that he suffers not because God has drawn away, but because God has drawn close to us convicts, drawn close through a manger, drawn closer to us than the hard prison cell walls of a cold Nazi prison.

1 Dietrich Bonhoeffer Works, vol. 8, Letters and Papers from Prison (Fortress, 2010), 343–347.
2 Ibid., 188.
3 Luther's Works (Fortress, 1957), 31:53.
4 Dietrich Bonhoeffer Works, vol. 8, Letters and Papers from Prison (Fortress, 2010), 224–226.