During the opening of the book Scrooge's nephew, Fred, arrives to invite Scrooge to Christmas dinner. During his speech about the importance of Christmas, Fred says that Christmas cannot be separated from "
the veneration due to its sacred name and origin." By this he means that Christmas cannot be separated from the worship of Christ, who gave it its name (it is literally the Mass for Christ, the name is just a shorter version of Christ's Mass.) This is slightly ironic as Dickens says that the celebration can't be separated from Christ and then writes a book about Christmas which never even mentions him. And what's more, because Dickens's book went on to radically change the way we viewed Christmas, the book probably did more to increase the distance between Christmas and man who it was originally supposed to celebrate than anything else.