Researching what's represented under the category of Christian fiction leads to many different genres. Each novel, whether romance, crime, suspense, or other categories falls under Christian fiction for one of at least three reasons:
     1. A novel may be classified as Christian fiction for no other reason than the book was written by a person who's a Christian. The stories they create may be no different than the other novels of that genre found in other areas of a bookstore.
     2. Other novels are considered Christian because they've been cleaned up. Many Christians will refuse to read a book if it's filled with graphic violence, gratuitous sex, and/or foul language. Writers have found a ready made audience for "sanitized" fiction, whether or not they're Christians or their books contain Christian themes.
      3. The third thing which places a book in the category of Christian fiction are the themes found within the main plot or subplots of the story. Some of the most popular themes include scenes of angels battling demons, a Christian facing a crises of faith, discussing the issues of today from a Christian worldview, and non-Christians searching for and finding faith in Christ.
     In my opinion, and it's only my opinion, in order to be classified as Christian fiction, numbers one and three must be true. While it's true non-Christians can write about Christian doctrine and Christians, once it's discovered they're not Christians, any conclusions they arrive at, correct or incorrect, concerning these things are questioned. The same can be said if the writer is a Christian; however, those conclusions are based on a set of Christian doctrine, whether or not we agree with those doctrines, not some theoretical and secular opinion about how the writer feels something should be.
     Number two must be true, at least in part. Violence, sex, and foul language are all a part of life in a fallen world. As long as these elements are essential to the story and not just used for a shock value, I see no problem incorporating them into the story. On the other hand, I can agree with the people who say some things can be left to the imagination and left out without altering the effectiveness of the plot.
     However you define "Christian fiction" is up to you as the book buyer and reader. May you always find the novels which get your imagination working, inspire you, or bring you joy.