Despite the obvious presence of ghosts, which one tends to loosely associate with religion, after-life etc. Dickens' work A Christmas Carol seems to offer a decidedly secular view of Christmas. The messages within the novel are only loosely related to Jesus, in that being nice and generous is the sort of behavior he was in favor of. As far as the holiday celebrating his birth, there is little mention of this in the novel. While it is interesting that a book written this long ago offers the secular view that many now hold, there is some question as to what role Dickens' work has played in shifting the emphasis of the holiday from celebrating the birth of Jesus, to celebrating the kindness, generosity and love that Jesus taught (without necessarily mentioning him).
Not only has Dickens' story been retold in many forms, including both an animated Disney version and a muppet version, but the overall theme has often been replicated. In a great many Christmas stories, the final theme, or realization is that kindness is the true meaning of Christmas. In Dr. Suess's story, the end of the story has the Hoo's (down in Hooville), singing and celebrating despite the loss of all the gifts, and decorations, proving that the material is inneffectual. In "It's a Wonderful Life," borrows Dickens' angel/spirit/ghost assisted time-travelling idea, to eventually show Jimmy Stewart (well, his character) that his life is "wonderful," again revealing the message that kindness and family are more important than material possessions, and losing one's company so that Mr. Potter can financially take over the town.
That's just naming a couple. This adherence to Dickens' theme suggests that in many ways, he helped to make Christmas what it is now.
Merry Christmas, and God Bless us, every one.