There are various themes in the book, with the overall theme of "there are no random acts in life".
The theme of the book changes as Eddie progresses through heaven, each theme being the lesson Eddie learns from each of the people he meets in heaven:
- Blue Man: Everything happens for a reason. There are no random events in life. All lives and experiences are interconnected in some way, and even the little things you do can affect other people's lives and experiences dramatically.
- The Captain: Sacrifices are a part of life. Everyone makes these sacrifices. Some sacrifices are big, and others are day-to-day small sacrifices, but they all make an impact in other people's lives.
- Ruby: The importance of releasing anger and granting forgiveness. There is always more than one side to a story.
- Marguerite The power of love, even after death. There are multiple forms of love, some stronger than others. Lost love is the strongest kind of love, the kind that can be felt even across enormous distances.
- Tala: There's always a purpose for your life. You live for a reason the same way that people die for a reason. Where you are today is a combination of all your past actions, decisions, and the way the people around you have affected you.