I write inspirational fiction, in which the main characters live with a Christian mindset.
Inspirational fiction has progressed from safe and syrupy to real-world drama. The characters tackle their challenges through a realistic plot, action, and emotions.
Do not expect the plot to halt while I get on my soap box or explain the plan of salvation to a character. I was amused, in fact, when a character in one of my novels, broken with the weight of his life gone awry, confessed his need for a relationship with God. That wasn't planned at all. And it hasn't happened in a novel of mine since then.
Another thing you can expect from inspirational fiction is a satisfying ending. You should be able to close the book (turn off the e-reader) with a sense of peace, happiness for the characters, and a satisfying conclusion.
We are spiritual beings, searching for answers to conundrums, relationships to others and to God. Spiritual beings required spiritual solutions to their problems.
God did not promise us that our lives would be easy; in fact, He guaranteed we would have problems if we live a Christian life. Inspiration, then, is derived from walking with a well-drawn character through a "true fiction" situation. We laugh, we cry, we see how someone else with a godly worldview might have created a life. That's the backbone of "inspirational fiction."