But to the surprise of many, including Steenburgen, the show did not turn out to be cringe-inducing.
"I can always tell when people have seen the show," Steenburgen said. "They get that the humor is huge, it's very irreverent. That it's edgy in its own way. It's all the things you wouldn't expect from a show about God."
It's a hit, too. "Joan of Arcadia" has been a surprise success on CBS Friday nights, winning a People's Choice Award as the best new TV drama and minting a new star in Amber Tamblyn, who plays Joan.
Barbara Hall, the series' creator, had it worse than Steenburgen. Until it aired, all people knew about "Joan of Arcadia" was its one-line description as a "modern-day Joan of
"Besides the fact that when you try to pull something off like this you're risking enormous public failure, just because the idea is so hard to pull off, I knew I'd have to live through the months of people only hearing that line," Hall said. "It sounds terrible to me too."
The natural inclination was to draw comparisons to the broader spiritual focus of "Touched By an Angel," which CBS had just canceled.
Steenburgen read the script because she saw it was written by Hall, producer of "Judging Amy" and writer for the early 1990s favorite "Northern Exposure."
Critics have similarly seized on the intelligent quirkiness of "Joan of Arcadia." Joan, whose father is an ex-police chief and brother is wheelchair-bound following an accident, meets God in the guise of different characters every week: a woman in the cafeteria lunch line, a high school hunk.
God gives Joan a series of assignments, often hard to fathom. She's asked to build a boat, join the chess club, ask a bully to the school dance.
The direct pipeline doesn't give her divine powers. Joan would love to use her newfound ability to lift her brother from his wheelchair, for instance, but God doesn't work that way.
"Even though Joan has guidance from God, nothing gets solved in her life because of it," Hall said. "She still has to go through the same dilemmas and struggles that everyone else does."
Neither does the series over-rely on its signature device for intriguing plots. It was almost irrelevant to the story in one standout episode, where a teenage boy was afraid to read the letter left behind by his mother after she committed suicide because he worried it was his fault.
While the Rev. Christopher Robinson, a professor of religious studies at DePaul University, said he was occasionally moved to tears by "Touched By an Angel," he finds "Joan of Arcadia" more complex and clever.
"Its unpredictability is one of its best selling points," Robinson said. "I hope it doesn't fall into a situation where patterns surface, where in the end everyone lives happily ever after because Joan is a good person."
Most Christians stop their religious education in elementary school, so they approach adult problems with a childlike view that religion is all about rules, Robinson said.
"Joan of Arcadia" moves beyond that without being preachy, he said. "It doesn't make God look silly or mundane. It makes God look more complicated, and that's a good thing."
Hall, like Robinson, is a practicing Roman Catholic. Yet Hall has also been a Methodist and Buddhist in her life; Joan's fictional God isn't attached to one particular religion.
A friend told Steenburgen about how some groups trying to help teenagers resist drug and alcohol abuse have screened episodes of "Joan of Arcadia" because it helps them understand the concept of a higher power that is non-denominational.
Despite having a close family, Joan keeps her divine conversations to herself (she did hint about her secret to a dying child in one episode).
Hall believes that to be realistic.
"I have a 12-year-old girl and she doesn't tell me anything," she said. "She won't even say what she had for lunch."
Her daughter was the original inspiration for the series; Hall tried to imagine what it would be like if God had talked to her.
What hasn't been revealed to viewers is why God has chosen to communicate through a 16-year-old girl. Hall said it won't be addressed this season, but probably will in the future.
"I think that question has already been answered," said Tamblyn, nursing a slight cold while waiting for an order of tea at a Hollywood restaurant. "I think the fact that Joan is ... just average, I think that's the whole message, that you don't have to be a special person in order to talk to God."
Tamblyn, the daughter of actor Russ Tamblyn, is dealing with a budding celebrity stature, her face popping up on magazine covers. She described a mild mall mobbing by young girls as she waited to get Indian food.
"Two days later, I had someone come up to me who was, like, 6-foot-2 and had his septum pierced and had a tattoo on his shaved head and sleeve tattoos with a really, like deep voice that told me he and his mother watch the show," she said.
Few young actresses would resist the chance to star in a network television drama. This had the added benefit of being good, Tamblyn said.
After reading the first script, she said, "I felt I knew the character instantly. I visualized how she would look. I knew that it was a risk, and not enough risks are taken on television."
By David Bauder