Hugh Grant gets top billing as Heretic‘s biggest star, but Chloe East and Sophie Thatcher are the heart and soul of the film.

In the new religious horror movie from Scott Beck and Bryan Woods, East (The Fabelmans) and Thatcher (Yellowjackets) play Sister Paxton and Sister Barnes, a pair of Mormon missionaries deployed to the mysterious Colorado compound of Mr. Reed (Grant). As they begin to discuss their faith with the disarmingly charming homeowner, Grant’s character gradually grows more antagonistic toward the concept of organized religion, prompting Barnes to consider second-guessing her convictions and making Paxton more resolute in hers.

The two actresses both grew up in the Church of Jesus Christ of Latter-Day Saints (colloquially known as LDS or Mormonism) — though the directors didn’t know the actresses’ backgrounds when they auditioned.

“They were raised Mormon, and that was not necessarily on our bingo card when we were casting,” Beck tells Entertainment Weekly. “We weren’t like, ‘We have to find two actresses that were raised Mormon.’ But the reason they won the role is because they were so true when they performed it. We kept going back to our casting director, asking, ‘Are there more people like these two? Because there’s a truth there.'”

He continues, “We didn’t know that they were raised Mormon. We could just feel it; we could sense it. We heard it in their voices and the approach. And I think that the way they played the characters, they brought the utmost respect because they have Mormon families. And so they share the empathy and love that we also share for those characters.”

Thatcher and East both tell EW that they immediately felt an innate understanding of Sister Barnes and Sister Paxton — and they both selected outfits that they knew young Mormon missionaries would choose during their self-tape auditions. “We did chemistry reads with different girls, but I had heard from our casting director that Chloe grew up Mormon and has Mormon family, so there was that instant connection,” Thatcher says. “We found a lot of parallels in our lives and connected, and I think they saw that and saw the truthfulness behind our connection to the religion.”

East says her religious upbringing informed every second of her work in Heretic. “It was everything to my performance,” she says. “A lot of the choices I made and little idiosyncrasies were all things that I’ve pulled from going to church.” The actress clarifies that she wasn’t as persistent an evangelist as her character: “Growing up, I never was the one to tell my classmates about the church and why they should join it. I never went on a mission or anything.”

But Paxton’s character still seemed almost disturbingly familiar to the actress. “I just felt like I knew this character in my bones,” she says. “I wish I didn’t know it so well, and I had to research stuff, but I was like, ‘I got it.’ I, unfortunately, was this person or have this person inside of me that I can use in this movie. But it is very nice to have a role that does come somewhat naturally.”

Thatcher had a similar experience. “It felt much more personal than other projects,” she explains. “It felt like I was tapping into something I knew a while ago, but it was easier to tap into because I just thought of myself when I was younger: how I held myself, how I presented myself, and just thinking about my family and specific ways and how they talk, how they just present themselves. I just had my mom’s side of the family very much in mind. It felt very innate.”

East believes Heretic provides a more nuanced depiction of her family’s faith. “You always see very extreme takes — The Book of Mormon musical and even Under the Banner of Heaven is a very specific kind of extreme Mormonism mentality and extreme,” she says. “I know a lot of Mormon friends who look at that series, and they’re like, ‘We’re not like that. That’s weird. That is not us.’ And then you have a more truthful, more current, modern version of Mormonism that a lot of my friends identify with. And you just don’t see that a lot. You don’t see this version of Mormonism played out.”

Childhood friends Beck and Woods come from different religious backgrounds. “I was raised Presbyterian, going to church every single Sunday, doing vacation Bible school. Church and religion were basically my formative years,” Beck explains. “And when I was in high school, I met my girlfriend, now wife, and she is Jewish and came from a Jewish family. And so when we got married, it was like this combination of religious backgrounds.”

Woods, on the other hand, married into a Mormon family. “I was not raised Mormon,” he clarifies. “The idea of Mormons, it was like, ‘Who are these people? What is this?’ Didn’t really know much about it until I met my wife. And we have subsequently a billion Mormon friends. But all of our friends and family all belong to different faiths. I mean, we have friends who are Scientologists, if you can believe it. We have lots of atheist friends. It runs the gamut.”

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Those connections to friends and family across a multitude of faiths mean that the filmmakers feel strongly for their main characters — they see themselves and their loved ones in the movie’s core trio. “We have so much love and empathy for these two women,” Woods says. “The movie’s very personal, so all of the characters, they feel like they’re all a little bit between them. Mr. Reed and the sisters — they all feel like people we know and love.”

The filmmakers took special care to take the characters’ faith seriously. “It’s so easy in media, especially with Mormons, to kind of paint a comedic picture because there is a naivete, and there’s just elements inherent in the Mormon culture that could be comical to outside eyes,” Woods says. “We’re not necessarily shying away from that because, again, I came into a Mormon family, and there were things that were amusing to me as an outsider, and so we were pushing those buttons. But the deeper we got into the Mormon culture, the more obvious it became that there’s an intelligence and a warmth and a sincerity and all these beautiful things that we really respected.”

Heretic is now playing in theaters.