For decades, “The Exorcist” was considered the standard-bearer of horror movies, a full-throttle ride through the dark side that was nominated for 10 Oscars and became the highest-grossing horror film of all time. But in 2013, a movie called “The Conjuring” burst upon the summer movie scene to become a scary sensation in its own right – riding a controversy over its MPAA rating all the way to nearly $150 million (making it second only to “The Exorcist” in the genre) despite the fact it had no major stars in its cast.

The reason why “The Conjuring” drew so much buzz was the fact that it received an R rating without having any foul language or sex, and no graphic violence. Rather, it was labeled that harshly for “sequences of disturbing violence and terror”, reflecting the unbelievably tense and suspenseful tone that Wan managed to establish in detailing the true story of the famed Catholic couple Ed and Lorraine Warren.

The Warrens were the top non-clergy exorcists on the planet, having helped eradicate dozens of cases of alleged possessions and demon attacks among people worldwide. In the first “Conjuring,” they helped save a family from demonic attacks at their rural Rhode Island farmhouse, and in the new film they help a British single mother and her three young children who believe they are under siege from evil spirits.

Both movies are scary as hell, with the first widely regarded as second only to “The Exorcist” as the scariest film ever made, and the sequel ups the ante in scale and nearly in its ability to terrify viewers. Since the fun of these movies lies in the shocking surprises, I’m sparing details other than the fact that these films will thoroughly scare you, and am explaining how they attain their unique mix of faith and fear.

Is it worth seeing? Despite the fact it has totally clean language, and again no sex or nudity, this is a very intensely scary film. If you can handle a truly unsettling mix of faith and fear that will stick with you and give plenty to think and talk about long after the movie is over, then by all means check it out.

There is little or no graphic violence, but you will see a horrifying demon in a nun’s habit at points throughout the film, as well as spinning crucifixes and all sorts of other creepy uses of Catholic iconography – but, to be clear, it’s all in the service of good. These films’ ability to reach a horror audience that normally would steer clear of anything religious makes them some of the most invaluable films to come out of Hollywood these days. If you’re not into scary movies, definitely stay away.

As with the first, director James Wan and the co-writing brother team of Chad and Carey Hayes - who are self-professed devout Catholics - surprise viewers by transcending the usual shock factor of such demon-possession films with a bracing existential battle centered around the very concept of good versus evil itself.

“These movies are not directly Christian films, but faith is integrated into them,” says Chad Hayes, speaking from the movie’s press day at the Four Seasons Hotel in Beverly Hills. “The idea beneath it all is that when good people do nothing, Satan prevails. Ed and Lorraine only literally had their faith as their weapon, with no cellphones and no gadgets. We learn much more about them and their faith because we’re not having to explain everything about them like the first time, and we could show what drove them into their calling.”

“I believe that people identify with this because it’s a true story they can look up and see that it happened,” adds David Leslie Johnson, who teamed up with the Hayes brothers to write the sequel. “Because the characters have this strong faith and you know that they will find a way to a happy ending, this becomes something very rare: a positive horror film. So there’s a sense of hope with them. It’s not so much the quality of the death and despair, but of the hope you get at the end.”

Knowing that “The Exorcist” was notorious for having suffered the deaths of nine people - cast or crew members or their close family members – during its legendarily dark production, Carey Hayes was happy to see that the production invited a Catholic priest to come bless the sets on the first day of shooting the sequel.

For Wan, who has also frightened audiences as the co-creator of the “Saw” and “Insidious” horror franchises, that visit was more of a fun insurance policy for the shoot than a serious endeavor. Yet it’s clear that he’s been fascinated to see the responses to his films, going from pariah status labeling him as a purveyor of “torture porn” with “Saw” to a master of suspense with Christian heroes in the “Conjuring” films.

“When I made ‘Saw’ I got accused of being fascist, with ‘Insidious’ they said I was godless, and now with ‘Conjuring,’ some say there’s too much God,” says Wan. “It’s really interesting to see people react to my three sets of horror films. These characters are such devout Catholics, there’s no way to make a movie about them without touching on that world and their view of it. They use their faith as a crutch to stand on, and their love for each other, and I thought that was such a dynamic thing to show in a movie.”

“The Conjuring 2” opens nationwide Friday.