Christmas
Because Skipping Christmas is set during the Christmas season, the theme of Christmas features prominently in the novel. At the start of the novel, the Kranks are disillusioned with what they see as the excesses of Christmas — most significantly the amount of money they spent on gifts and parties. However, the Kranks are eventually taught a valuable lesson about Christmas: it isn't about the material things; it is about the family and people you spend it with. To that end, they give the tickets to the cruise the couple was going to go on to a couple who would appreciate it much more.
The power of forgiveness
The power of forgiveness is another important theme in the novel. In Skipping Christmas, the Kranks' neighbors are disillusioned with their neighbors because of their disinterest in and disgust for Christmas. To express their displeasure with the couple, the Kranks' neighbors start to annoy and prank the couple, hoping that their actions will inspire the Kranks to decorate their home for Christmas and for the competition. The neighbors, in other words, hate and hold a grudge against the Kranks for their disinterest in Christmas.
Eventually, though, when the Kranks change their mind and decorate their house (and put on their famous Christmas party), their neighbors stop their antics and start to treat the Kranks better. They also forgive the Kranks, and come together with them to welcome the Kranks' daughter and make her feel welcome at their Christmas Eve party.
Joy
Joy is perhaps the most significant theme in the novel. In each thing they do, the Kranks aimed to find happiness and joy. For instance, they decide to avoid the negative feelings they typically have by going on a cruise to the Caribbean. Despite their best efforts, the Kranks are often unable to find joy. They find fault in everything — Christmas, their daughter, their neighbors, among many others — despite everything seemingly being okay.
