It’s been nearly a decade since author William P. Young’s novel, The Shack, was published, selling over a million copies within the space of a year and going on to be one of the most influential pieces of Christian fiction ever produced.

There’s a good reason why The Shack went from self-published unknown to selling over 15 million copies between 2007 and 2011: through the novel, Young taps into the collective desire for a truly loving God in a time when many have become disillusioned with organized religion.

Now, on March 3rd, The Shack is finding new life on the big screen with its theatrical debut, starring Sam Worthington, Octavia Spencer and Tim McGraw.

We were lucky enough to have a chat with lead actor Sam Worthington, who portrayed the character of Mack Phillips, a man who, after the death of his young daughter, spirals into a deep depression and begins to question his faith in a good and loving God. Worthington, who was changed by his experience with The Shack, reveals insights that shed light on the depth and power of the film.

Here’s what he had to say on what led him—an action hero of Avatar and Terminator fame—to the role.

“To be honest, I read the script and I can’t really tell you why I said I wanted to do it. I had a visceral reaction to the script. Normally you pick a part because of the other actors involved or there was something you needed to say in the story, but I just had a feeling about it. I called the producers and said, ‘I don’t know what it is, but this thing really got me, and I’d love to do the film.’”

When we pressed a little about what drew Worthington to the script, he revealed something that millions of readers have been saying since the book’s release: the story gave him something he needed.

“I think maybe there’s something in it of those arguments that I’ve had with the world—I think maybe it was something about this man’s emotional journey, where I went, ‘Well, I’ve been a frustrated guy. I’ve built my own Shack. I’ve got to learn to forgive.’ I don’t know—those kinds of things really echoed with me. Film making is problem solving, and these are great problems to try and solve.”

The Shack is a parable for the anger and frustration and grief and guilt that we carry and are burdened by. We build these things in our lives, and we don’t have the tools to get out of them. If the movie and the book can give you those tools and give you those lessons, that’s a very interesting message to get across. So I think that’s what I was discovering as well: what are the tools, then? How do you move through forgiveness? How do you get to the other side and gain some clarity in your life?”

That’s the thing about the Bible, as well, you know. The Bible is stories, and out of these stories you gain insight into, alright, how can I parallel that with my life, and how do I use that to make me a better person, and use the lessons they’re teaching to make me a better person? So The Shack had that same kind of effect for me.”

The film, despite its emotional content, is no stranger to humor—the surreal weirdness of seeing God making biscuits in the kitchen will put a smile on audience members’ faces. When we asked Worthington what it was like to act out a nice country dinner with the God of the universe, he had this to say.

“That’s the weirdest thing, you know. I would tell my friends what I was doing, that I’m doing a movie where a guy who spends the weekend with God, Jesus, and the Holy Spirit. And you could see my mates looking at me like I’d lost my mind, not only in what I was saying, but just in the fact that I was going to do a movie like that.

The way it works, though, is that the scenes aren’t reverential—the scenes are done on a grounded level—almost two friends—that gives the film an element of truth, and out of that the arguments get a bit more gravity. So if you look at when people pray, you’re looking at God sometimes as the closest friend and only friend you’ve got left, so it’s not like it’s too overwhelming. I said that if we approach it that way, if Octavia approaches it in a grounded way, these arguments and messages will resonate more.”

It is in that very ordinary-ness that the film is most powerful. This isn’t a story of God speaking out of fire and thunder. This isn’t a grand narrative of His plans for humanity. This is a simple story of one man spending time with his Papa, something to which anyone, secular or Christian, can relate.

Worthington concluded with what he hopes people will take away from the film.

“I think it’s a hopeful film. That’s the main thing. I don’t have a nihilist view of the world—I want movies to kind of stay with you when you leave the cinema a lot longer than just crossing the lobby, and maybe promote conversation.”

And, indeed, the film is set to do just that. In addition to Worthington, we also had the pleasure of catching up with the author of The Shack, himself, William P. Young. A cheerful and and intelligent man who simply goes by Paul, his insights into his work were profound. But he had one thing to say that encapsulated the purpose of his book like nothing else.

“I grew up a modern Evangelical fundamentalist preacher’s kid, and [the purpose of the novel] was to say ‘Look, you know, I don’t want you to try to have a relationship with the God I grew up with. But let me write, as best I know how, the character and nature of the God who actually showed up and healed my heart.”

And that’s it. That’s why The Shack has changed so many lives, and will continue to change more when it reaches entirely new audiences on March 3rd. Whatever your beliefs, this film has something to offer–the very real and very grounded struggles of the protagonist will feel familiar to many, and the tools and lessons provided by the story of The Shack might just be what you need to help you through the most difficult and confusing questions life has to offer.