Well, because they’re terrible, first of all. Via Meadia has some further thoughts:
What accounts for the failure, aside from outliers like The Passion, of religious-themed movies to hit it big at the box office?
Part of the answer is of course quality. A good Christian movie has to be first and foremost a good movie, and making good movies isn’t easy. Christians certainly aren’t doing themselves any favors in this regard by hiring politicians rather than artists to lead studios.
Ah, but! Maybe Christian movies are more popular, we’re just incorrectly classifying the movies that are “Christian.” More from VM:
…Christian movies are hard to categorize. Historically, religious bestsellers (and they have been legion) cut across many different genres: simple stories told clearly and simply about ordinary lives transformed by encounters with God, the adventures of great heroes of faith whether from the Bible or other sources, works of fiction that present spiritual themes in either heroic or apocalyptic dimensions. JRR Tolkien’s extraordinary fantasy trilogy was (and still is) considered one of the greatest works of Christian fiction in the 20th century, and while the films don’t exactly dwell on the profoundly Christian spirit that informs every line of the story, they don’t exorcise that spirit either.
When you set out to explicitly, overtly deliver a Christian message, you’re not making a movie; your making a sermon. Sermons can be good on their own, but they make crappy movies.
But any story of good vs. evil, of transformation, of sacrifice can be told from a Christian perspective. Stories like that, told in a compelling way, can do more to promote Christian values than any warmed-over morality play translated to the screen.
Maybe my standards have just gotten really low after a lifetime of watching Christians portrayed exclusively as hypocritical nutso scumbags in movies, but all I ask is for movies not to actively trash everything I believe in. If I get that, I feel like I’ve been to church.
So advice to Christian movie makers, focus more on story and less on alter calls. You don’t have to clear a very high bar for your work to be considered “Christian.”