This article speaks well about how literature in general, and specifically fiction, should be judged for its quality, not its author. If we consider other articles like Why Every Story and All of Literature Is Christ-Haunted, we will need to consider how to share our Christian perspective without having to make every piece of art utilitarian.
WARNING: The author freely quotes language that many Christians would find unacceptable. While I do not support such language, such is how nonbelievers talk. (On whether the author is a believer or not I cannot speak, but the perspective shared is valuable.)