A personal anecdote: I lost my first "professional" film-criticism gig over The Passion of The Christ.
It was the early 2000s, and I'd been hired off the street (well, okay, out of the video store) to be more or less the "expert" on a three-person local-access movie chat show. It all went pretty well up until the release of Mel Gibson's ultra-controversial Jesus movie.
I found myself called to a "meeting" with the show's producer and star, who wanted to talk to me about the pending review/discussion of the film. He'd gotten hold of a copy of an older write-up of it I'd had up on the web somewhere, in which I A) gave it a negative review and B) agreed with the various folks who'd called it "anti-Semitic." (I stand by both contentions to this day.) My "boss" was not happy, and took rather specific umbrage at my sympathy for the Jewish folks offended by the film.
I was informed - in no uncertain terms - that a negative review of the film was not going to be allowed on the show. That, essentially, the episode would be about praising the film, its message and its religious viewpoint. I was summarily informed that my services - on this and any future installments - were no longer wanted. (Just for atmosphere's sake, please note that this meeting was taking place early morning, in a van in an empty parking lot.)
I never saw the episode, and the show was ended shortly thereafter.
In telling a story, the first thing you need to do is hook your audience. I don't care if you're making a movie, writing a book or reading aloud to preschoolers - step one is "pay attention to this!" There are hundreds of ways to do this, but the quickest and most effective involve familiarity: "This is about you," "this is about something you know," "this is about something you care about."
This isn't exactly easy. You have to construct a narrative that plays to universal human experience but in a way that feels personal to an individual: "Well, I've never been a Tatooine moisture farmer aching to join the Rebel Alliance, but I have felt stuck in life, so I can relate to this." You have to be introspective, empathetic and skilled at the art of human understanding.
Or, failing that, you can cheat - or, rather, take a shortcut - by making your central theme or plot device some specific hot button idea or issue designed to provoke an immediate reaction. There are certain "big things" that most people have already made their minds up about - race, religion, politics - and if you say upfront that your story is about any of them, well, now more than half your work is done. They're already engaged with the issue, so now they're already engaged with your story.
Of these shortcuts, religion is easily the most popular, particularly in the realm of genre fiction and genre film. Being able to say "these guys are with God, the other guys are with The Devil" makes quick work of having to establish the why of who's good and evil. For a clear recent illustration of this, see The Book of Eli a post-apocalyptic actioner wherein the fact that our designated hero is protecting The Last Bible on Earth is supposed to be the answer to every "why are we rooting for this guy?" question you could think of. God is good, Eli is on God's team, therefore Eli the good guy. Cut, print, cue swordfights.
Exactly how much of Eli's Sunday School spiritualism is sincerely meant versus a cynical grab for attention, one can't say, but in terms of inspiring devotion vastly disproportionate to that usually afforded a generic post-nuke actioner dumped unceremoniously into the January dead-zone release schedule it's been a huge success. Religious conservatives have rallied around it with what can charitably be called glee, while my own citation of its fervor as a net-negative earned me... "interesting" feedback.