Pelham, Ala. (RNS)—Frank Peretti sat in the Amen Corner, a banjo on his lap, playing the theme song from “The Beverly Hillbillies.”

He was at the Christian bookstore here promoting his latest horror novel, “Monster.” His first novel, “This Present Darkness,” has sold more than 2.5 million copies since 1986.

“That was the book that broke the barrier for Christian fiction,” Peretti said. “It certainly made my career.”

Since the days when Peretti had difficulty attracting a publisher for his first novel, the Christian publishing industry has embraced Christian fiction and the market for spiritual-theme novels has exploded, led by the “Left Behind” series.

Peretti, in his 1995 novel, “The Oath,” employed an allegorical dragon that feasts on a mining town’s sinners and grows ever larger. In “Monster,” he takes a different approach to his spiritual storytelling. “I didn’t go into allegory,” he said. “It’s a real monster.”

But he does explore a topic that generates controversy in evangelical Christian circles. As usual, Peretti’s novel comes with a spiritual message for readers, woven into the adventure story.

“My goal is to make them think about evolution,” he said. “Evolution as a philosophy makes monsters out of all us. It removes all that makes us human—morals, virtue, love, honor, self-sacrifice. All those become illusory. I’m trying to raise some questions. Who is the real monster here? I do it through a monster story.”

In “Monster,” the featured creature is a Sasquatch, or Bigfoot.

“Let’s assume Bigfoot is a North American great ape,” Peretti said. “If it was real, what would it really be like? What would it sound like, what would it smell like, what would be its feeding habits? Let’s see how close we can get.”

Peretti, 54, grew up in Seattle and had a difficult childhood because of tumors in his jaw and tongue that forced him to talk with his tongue hanging out of his mouth. He wrote about that in a nonfiction book, “The Wounded Spirit.”

His only way of successfully relating to other kids was telling them monster stories, which he began writing down. By age 12, surgery and therapy helped him learn to speak normally.

At 19, he was playing bluegrass banjo in nightclubs and he joined a musical comedy act that played at Harrah’s in Lake Tahoe.

He married his wife, Barbara, in 1972, had a Christian music ministry for a while, took English and screenwriting classes at UCLA and was an associate pastor, assisting his father, who was the minister of an Assembly of God church in Vashon Island, Wash.

Peretti had been working in a factory making snow skis for three years when “This Present Darkness” became so successful that he quit in order to write a sequel. Pastors urged their congregations to read it, and Christian singer Amy Grant touted it at her concerts.

Today, he writes five hours a day. “I set a kitchen timer,” he said. “I just put in my time.” His wife is a painter who also teaches finances at a drug rehabilitation center for women.

When he’s not writing on a laptop computer in his northern Idaho home amid 120 acres on the Coeur d’Alene River, the licensed pilot flies airplanes and plays banjo in a bluegrass band. He takes his banjo on the road and plays on occasion during his public appearances.

“I’m not a hermit,” Peretti said. “I live back in the woods, but we go to church, we have a circle of friends. People in town know us.”

His bluegrass band often travels with him when he does public speaking, and he turns lectures into concerts.

Picking up the banjo, Peretti strums and picks out a tune, expressing regret that he didn’t play for a long time. “I put the banjo aside for 20 years,” he said. “If I had been practicing all that time, I’d be really good by now.”