Does anyone have a special book or a passage that they always read at Christmas?
I do and it is A Christmas Carol by Dickens. For some it is the Christmas chapter from Wind in the Willows, for others it is a poem or an essay.I always read the Dickens because my Grandpa , a Methodist Minister dressed as Dickens in his Victorian suit, sat on the stage and recited it by heart. In this way he raised funds for his chapel, and apparently, it was wonderful to see as he had a compelling stage voice.
http://i.telegraph.co.uk/multimedia/archive/02794/dickens-1_2794642k.jpg

The Little Match Girl by Hans Christian Andersen

http://www.online-literature.com/hans_christian_andersen/981/

and

The Gift of the Magi by O. Henry

https://www.auburn.edu/~vestmon/Gift_of_the_Magi.html

Both of these stories, in my opinion, embody the spirit of the season... a consideration for others that is often lacking when marveling at all the shiny lights and tinsel and ribbons and bows.

Yes! I love both , and always read them to the students(and cry buckets).

The Christmas sections from Shirley Jackson's books about raising kids in a small town, "Raising Demons" and "Life Among the Savages". She calls those books "a disrespectful memoir of my children".
Each book has a chapter set at Christmas, and they are appropriately sentimental, with just a little bit of tartness.