The Sunday Assembly—the so-called "atheist church" that has been spreading all over the world—has received a 'super size' endorsement from filmmaker Morgan Spurlock.

Spurlock, an author and filmmaker perhaps best known for directing, producing, writing, and starring in the Oscar-nominated documentary Super Size Me, will host two services for Sunday Assembly's Nashville group tomorrow.

A "godless congregation that celebrates life," the Sunday Assembly has made some serious waves since its early 2013 launch by British comedians Sanderson Jones and Pippa Evans, and today it has over 30 affiliated groups.

I spoke at Sunday Assembly's first meeting in the U.S. last summer and have been monitoring their rapid growth since. (They were a clear choice for inclusion in my list of 10 defining moments in atheism for 2013.) So when I heard that Spurlock would be hosting Nashville's Sunday Assembly this weekend, I wanted to find out why.

Spurlock—who most recently directed One Direction: This Is Us and is currently filming the second season of Inside Man for CNN—spoke with me about why he is an agnostic, his thoughts on religion and community, what he likes about Sunday Assembly, and his experiences with Tennessee’s Muslim community.

Chris Stedman: You're hosting Sunday Assembly in Nashville this weekend. Why?

Morgan Spurlock: We're doing an episode of our show [Inside Man] exploring religion in America. There are over 11,000 churches in Tennessee—700 plus in Nashville alone. There's a little something for everybody, whether you are a Catholic or a Baptist or a Muslim—and I find it really interesting that [Sunday Assembly Nashville] has started to rise up in the middle of what is quintessentially a very strongly religious area. Especially when you put that side by side with the fact that 20 percent of Americans today are religiously unaffiliated, including 1 in 3 people under the age of 30, I feel like there’s an interesting topic to explore around why people are feeling attracted to something like Sunday Assembly.

CS: But you're not just profiling them—you're actually getting involved and participating.

MS: Well, that's kind of what I do with everything. I take you inside issues and give you an inside point of view of things you wouldn't otherwise get to see.

CS: So what are you expecting from Sunday Assembly? What are you looking forward to?

MS: I'm looking forward to the experience. I'm looking forward to seeing what a nonreligious church is going to be about. The folks that run the Nashville Sunday Assembly talk about how there have been Christians who come out because they're a very, very welcoming group of people who say that, whatever you believe, you can come be a part of this. Their whole idea is that Sunday Assembly is a celebration of life—so anyone can come celebrate this wonderful life we're all living together.

CS: You identify as an agnostic, right?

MS: Yeah. I grew up in a moderately religious family. I grew up Methodist, went to church a lot—probably the majority of my life up until I left high school—was baptized, you know, the works. I think that [changed] once I started traveling around the world and interacting with people of various religions who believed themselves to be on a path towards heaven or righteousness, while other [people believed that there is] only one path and that everything else is wrong. Along the way I've met incredible, wonderful, beautiful people and I started to have an issue with the idea that they aren’t on the same level as people of other religions. It made me question the validity of some of those beliefs.

Where I ended up at the end of this is knowing that I don’t know. I do believe that something marvelous and wonderful connects all of us on this planet—whether that be "the force" or whatever, there are things that connect us and I find those moments beautiful. I feel it when I interact with people all over the planet, and I think that that is part of what people get out of a church relationship or a community fellowship.

CS: You're visiting Tennessee for your show Inside Man. I saw that you also recently spent time there with Remziya Suleyman, director of policy and administration of American Center for Outreach—a nonprofit that empowers Muslims to engage in their broader communities. Can you say more about your experiences with the Muslim community in Tennessee?

MS: Here in the middle of the Bible Belt there are quite a few Muslims. I think there's something like 65,000 Muslims in the state of Tennessee who are just finding their place in the middle of a highly Christian environment—and for them to be here and express their freedom of religion is fascinating.

CS: Do you see commonalities in the experiences of some of the nonreligious folks you’re meeting through Sunday Assembly and some of the members of the Muslim community you've met?

MS: At the end of the day everybody should see the value of coming together. There is something that we all get out of community. When you are part of a community you live a healthier life. You're happier. One of the things church does really well—what it did for me—is create a fantastic sense of community and of belonging. So the [Sunday Assembly] folks are saying, "Listen, why can’t we create that for ourselves?" I find that really interesting, and it is growing exponentially. People all over the world are contacting them who want to start Sunday Assemblies in their own towns—I think that’s pretty amazing.

Season 2 of Inside Man premieres April 13 on CNN, and the episode featuring Sunday Assembly should air in May. Click here for more information on Sunday Assembly Nashville.