For several years in a row I hosted an online writing workshop, part of the Catholic Writers Online Conference.
The title of the workshop was Ten Commandments for Catholic Fiction Writers. In it I addressed some of the common fiction writing problems I frequently saw during the time I edited Catholic-themed fiction over at Idylls Press. Most of these issues were just a faith-based variant of the same flaws one sees in a lot of “controversial” fiction—telling, not showing; drawing heroes and villains along strictly ideological lines; deus ex machina plot turns, etc
A back-burner project of mine is to expand the material from that workshop into a book aimed at all fiction writers who deal with controversial themes.