Brian Sibley surveys the creation and many adaptations of A Christmas Carol.
A Christmas Carol is not about the birth of Jesus. Although Scrooge undergoes a conversion, it is not one of religious faith. Regrets of the past and being forced to confront his inevitable death don’t lead Scrooge to a concern about the afterlife; instead, he wants to make amends and improve the lives of others in the present.
Regarding baby Jesus, Sibley has written a thoughtful and sensitive fantasy interpretation of the event, in Joseph and the Three Gifts: An Angel’s Story.