One of the major themes in Alice Sebold's The Lovely Bones has to do with the power of love to guide the process of grieving and healing. When the novel opens, the reader learns immediately that Susie Salmon is already dead. As the novel unfolds, Susie's family is shown at various points in their grief over Susie's death and then grappling with the knowledge that she has been murdered. Susie's father Jack takes Susie's death particularly hard and goes through every possible method to try to find her body and her killer. He continues this struggle even after the authorities have given up much hope. Some might argue that Jack becomes obsessed with his search for the truth and that he is not allowing himself to accept Susie's death. However, as time moves on, his love for Susie takes over him and he begins to process his grief so that he can move on with his life.
Similarly, Susie is caught in the "in-between." She cannot move on because there are many things that she has left undone, namely her unrealized love for Ray. She regrets that she never got to have a first kiss, so she takes over the body of Ruth so that she can come back to kiss Ray. After this expression of love, Susie can move on into the afterlife.
So, The Lovely Bones has to do with the power of love to aid in grief and healing.
Initially I actually wondered myself as to what the point was for the story The Lovely Bones, but after hearing an interview with the author on a television show; I was a little clearer on it. The author wrote the book to take a look at an alternative plane of existence. Christians hold the idea of heaven but no one comes back from there to tell us what it is really like. There are books with people who had seen the light but returned from it.
The author is trying to make a point that when one dies they may go to a different plane of existence. She was toying with the "what ifs" and wanted to be wrapped around a family who valued each other but ended up with tragic issues following their daughter's death.
"Once upon Earth I saw her as Abigail, and then I let it slip effortlessly back-"(49)