After God said "Ha!," Julia Sweeney said "No!"

"It's really because I take you so seriously that I can't believe in you."

— Julia Sweeney, in "Letting Go of God"

You might think coming out as an atheist would be no big deal in 21st Century America.

Wrong.

When Julia Sweeney performed excerpts of her solo play "Letting Go of God" on the popular public radio show "This American Life," response from listeners flooded in.

And when she spoke about her metamorphosis from born-and-bred Catholic to nonbeliever in a conference on religious skepticism, Sweeney's devout parents in Spokane were none too pleased. In fact, they were horrified.

Yet the cheery-faced comedy writer-performer and former cast member of "Saturday Night Live" (her specialty character was the androgynous dweeb Pat), did not back down.

Sweeney mended fences with her family, but stuck to her new-formed views. And she says "Letting Go of God," which debuted in Los Angeles in 2004, has drawn so much interest it may resurface soon in a Broadway run, and get turned into a feature film.

Saturday at the Paramount Theatre, Sweeney will offer segments from the show and chat about its origins with "This American Life" host Ira Glass.

She is likely to inform the audience that she's a spectacular example of how adult Bible study can backfire.

It all began six years ago, explained the 44-year old humorist (who has also served as a staff writer for TV's "Desperate Housewives" and "Sex and the City"), during a phone chat.

"I was recovering from a terrible break-up with a man, and I was really depressed for about eight months," Sweeney noted in her familiar, chirpy voice.

"Then two things happened. I couldn't sleep for nights on end, and had this experience of feeling God's presence was in the room, like something supernatural was going on."

The other omen was the arrival of two young Mormon missionaries at Sweeney's door. "Spokane is very Mormon and Catholic, so I was raised around Mormons. When these two boys arrived saying they had a message of God, it seemed significant."

Sweeney soon began attending Mass regularly, and joined a Santa Monica congregation. "Before that I was never a fervent believer," she noted. "I always felt Catholicism was more of a cultural thing for me.

"But rejoining the church as an adult, I really got involved religiously. And once I actually read the documents upon which the church was based, I was completely horrified. That was the end of it for me. I couldn't separate the culture from the dogma."

Turned off by what, in her reading, were harsh edicts, violent retributions and unlikely feats scattered throughout the Old and New Testaments, Sweeney began a deep examination of her core belief system — and religion's role in society.

She had discussed faith before onstage, in her first solo show, "God Said Ha!" In that monologue (later a book, and a film produced by Quentin Tarantino), Sweeney candidly, movingly plumbed the anguish and darkly absurd humor of suddenly facing her own cervical cancer, while caring for a brother dying of another form of cancer.

Of the relief she, and others, have found in religion in times of illness and grief, Sweeney says, "It is comforting to imagine there's a power that knows you, a consciousness cheering you on.

"But if you pull the camera back it becomes horrifying. So was it God's lesson for my brother, to have him die of cancer at 32? If you look at that in a bigger way, it's really awful."

Though she no longer believed in "divine" messages and miracles, Sweeney kept seeking. She tried self-help philosophies, studied world religions. And she still calls herself "culturally Catholic" and attends church sometimes. ("All other religions are like Off Off Broadway, but Catholicism is opera at the Met!").

But Sweeney today might best be described as a scientific humanist, who finds great meaning in astronomy, biology, quantum physics.

"With science, I felt like there was a method of critical thinking I could apply to religion," Sweeney noted.

"Science doesn't give you methods of living your life well in community with others. That's why religion is never going away. We're social animals, we need ritual and community and reminders to be compassionate. But the dogma, the mysticism, the supernatural stuff ... "

As Sweeney observed the expanding role of religion in politics and education in recent years, the script for "Letting Go of God" took shape.

"President Bush was speaking in terms that were more religious than in previous administrations," she observed. "And I was horrified by 9/11, as an example of what devout religious fanaticism in any religion could do to people.

"I could never believe those people [in the Twin Towers] were destined to die, that it was God's plan for them."

Sweeney only half-jokingly calls atheists "the most hated group in America" today. But "Letting Go of God" won critical praise in L.A. (One review termed it "a window into a life examined that all but the most doctrinaire can appreciate").

And Sweeney reports, "Every day I get a letter from somebody telling me they hate me, but that's minor compared to all the positive response I get."

Healthy, raising a young daughter and involved with "a fantastic boyfriend," Sweeney says life is good — though she's still "grappling with religion."

"The world is modernizing so quickly, people want to latch on to things that seem familiar," she mused. "Religion identifies people, roots them in a tradition bigger than themselves, reminds them to be compassionate. I get that."

So what beliefs guide her today? "Every time I describe it I sound like a 'Star Trek' convention, but I do wish we could worship the sun, the moon and the stars. For me, just reading about astronomy and what conditions were right on Earth for life to evolve, how all those molecules became me, is so profound."

Misha Berson: mberson@seattletimes.com