"The Problem of Pain," by C.S. Lewis, is a non-fiction work that looks at the title phenomenon in a Christian theological context. The chapters in the book look at human pain, animal pain, divine omnipotence, human wickedness, and other theological/philosophical concepts.
I found "Problem" to be a curious book. Some parts are well-written and thought-provoking, some parts are dull. Some parts just seem self-indulgent and even silly; at its worst the book reads like an eggheaded parody of theology. The chapter on hell is particularly unsatisfying; I found it to sound patronizing and frustratingly vague at times. But the book as a whole is thankfully enlivened by delightful flashes of wit.
Theologically, Lewis seems to be at odds with strict biblical literalism; in chapter 5 he appears to endorse the idea of biological evolution, for example. Despite my reservations, I feel that this is a worthwhile book for both Christians and those of other belief traditions.