He greeted his TV crew and pastoral team, took a leather-bound Bible out of his briefcase and hurriedly ate a banana. Then he changed into a dark blue suit, sat down in a chair on the corner of the set and prayed quietly -- eyes closed, hands held a football length apart.

Three minutes later, he was on the air, live, talking to 250,000 viewers throughout Florida in earnest tones about sin, death, salvation and alligator attacks.

Five nights a week, Keller -- televangelist, ex-convict and founder of liveprayer.com, billed as the world's largest interactive Christian website -- brings a stark, fundamentalist message to broadcast TV.

He has shunned Christian cable-TV networks and pious, Sunday morning broadcast audiences for a 1 a.m. slot on six commercial stations in Florida.

`BIBLICAL TRUTH'

''I'm trying to be a voice of biblical truth in the marketplace, not preaching to the choir but in the same marketplace Oprah is, the same place Dr. Phil is, the same place Montel is,'' said Keller, whose show airs in Miami on WPLG-ABC 10, right after provocative talk-show host Jimmy Kimmel.

``Some people out there aren't going to like it, but so what?''

Like him or not, Keller is poised to increase his impact. In July, his show is set to air nationwide on stations in the i Network, formerly Pax TV, making him one of just a handful of evangelists to preach to a late-night broadcast audience.

Keller concedes that it may be tough to win viewers. The salesman-turned-preacher has a well-publicized criminal past -- he served nearly three years in federal prison for an insider-trading scam -- and will have to overcome widespread public mistrust of religious broadcasters.

With more than 1,600 Christian radio and television stations across the country, most televangelists minister to audiences on exclusively Christian cable channels in the wake of scandals that plagued prominent TV preachers such as Jim Bakker and Jimmy Swaggart.

`PUBLIC SKEPTICISM'

''Since the scandals in the 1980s, there have not been many TV evangelists trying to gain audiences on mainstream stations,'' said Quentin Schultze, director of the Gainey Institute for Faith and Communication at Calvin College in Grand Rapids, Mich. ``There is still a lot of public skepticism.''

While a handful of preachers buy airtime on Sunday mornings in local markets, Keller stands out in his planned attempt to reach a late-night national audience -- a $10-million-a-year endeavor that he says will be supported almost exclusively by advertisers.

Until now, Keller has paid the Florida stations for his 1-to-2 a.m. weeknight slot. He finances the television and Internet ministry's $2.2 million annual budget primarily through individual donors, he says.

Keller, 48, has a curly mop of bleached blond hair, a lanky, athletic build and throaty chuckle. On TV, he has a casual, intimate demeanor that moves callers to reveal things they might not tell a pastor, parent or spouse.

During a recent show, Keller heard from Tracy, a 19-year-old in Englewood, whose girlfriend was unexpectedly pregnant; from Patty, a cancer survivor in Clearwater who is addicted to painkillers; and from José, a 17-year-old in Lakeland who felt confused about his sexuality.

Staring straight at the camera, Keller slices at the air with his hands, telling his audience that homosexuality is a sin, non-Christians are going to Hell, and legalized abortion will bring the wrath of God upon the nation. Then he invites the audience to call and challenge him. The phone lines light up.

`PEOPLE FREAK OUT'

''If I sit there and say homosexuality is a sin, not because I say so, but because God says so, people freak out,'' he said. ``But it doesn't take any guts for a pastor to stand in the pulpit on Sunday morning and call abortion murder.''

Dave Boylan, general manager of Miami's WPLG-ABC 10, said Keller's show generates a mix of praise and hate mail.

''A lot of people say it's refreshing to have something a little different,'' he said. 'We have other people that say, `Why is this guy on TV?' ''

Sometimes, Keller's critics go on the offensive.

Michael Glassberg, who manages Internet operations for Bill Keller Ministries, said he spends two hours a day protecting liveprayer.com from hackers who try to post obscene pictures and disparaging comments.

''When he attacks like six groups in one night, I know I'm in for it,'' he said.

While Keller insists that he is not seeking fame or personal wealth, some are skeptical of his quick rise.

Cash that often flows through a media empire can corrupt even televangelists who start with good intentions, said Ole Anthony, president of the Trinity Foundation, a nonprofit religious watchdog group that investigates televangelists. Many TV preachers are now getting millions of dollars through sophisticated direct-mailing campaigns, Anthony said.

Last year, Bill Keller Ministries had revenue of nearly $1.3 million, according to documents the group filed with the Internal Revenue Service. Keller says he takes a salary of about $50,000 a year to support himself and his wife, Nan. That has required a bit of a lifestyle change; when he was selling stocks, Keller says, he never made less than $400,000 a year.

EARLY YEARS

William H. Keller grew up in Columbus, Ohio, as the oldest son in a devout Methodist family. Keller says he found Jesus when he was 12 and planned to go into seminary to become a Methodist preacher. After his father died when Keller was 16, he worked summers to put himself through Ohio State University.

He was a natural salesman. During his junior year in 1978, when he ran out of money, Keller set up a mail-order company selling computers out of his mother's basement. He tallied $5 million in sales the first year, quit school and scrapped plans for the seminary.

Keller later sold his company and invested in stocks. After losing everything in the 1987 stock-market crash, he turned to an insider-trading scheme, running illegal deals through an investment firm he started in the Cayman Islands. When the Securities and Exchange Commission filed a criminal suit against Keller in 1989, he told agents, in his words, to ``go fly a kite.''

''I was obnoxious. I was very arrogant,'' he said. ``I was 30 years old, I'd made a lot of money, I was still living pretty high, living a debauched lifestyle.''

Keller eventually served 30 months at a federal prison camp near Pensacola, where he earned a mail-order degree in biblical studies from Jerry Falwell's Liberty University.

After his release in 1992, Keller returned to Chicago and became an itinerant preacher. He lived on less than $20,000 a year, he says.

Frustrated that he couldn't reach audiences outside of church, Keller signed on as a consultant to a Christian TV network in Clearwater. But he quickly became disillusioned. ''To be very blunt, it's a hustle,'' he said.

WEBSITE LAUNCHED

Keller left and launched liveprayer.com in a cramped office in the back of Ace Motors, a St. Petersburg used-car lot run by retired police officer Clyde Walters, a supporter who gave Keller a free car and office.

With about 700 volunteers, most of them retired pastors, Keller responds to about 40,000 prayer requests that come to the website daily. He e-mails a daily devotional to more than two million people.

A couple of times a month, he asks for money. Recently, he has started to solicit donations on his TV show, telling viewers the money is needed to pay off his ministries' $500,000 debt.

Keller launched his TV show, Live Prayer with Bill Keller, three years ago to compete with some secular talk shows in what Keller views as a battle for souls.

''I don't hold back the truth,'' he said. ``I don't have a problem sitting in front of a quarter of a million people every night and telling someone they're going to Hell.''

Keller's occasionally caustic style can get him into trouble -- he receives up to 30 death threats a month, he said.

Other ministers who have publicly challenged Keller's fundamentalist views have found him aggressive and intractable. The Rev. Phyllis Hunt, pastor of the Metropolitan Community Church of Tampa, joined Keller in a panel discussion on religion and politics. The discussion quickly degenerated into a screaming match over the Bible and homosexuality, Hunt said.

''He was pretty predictable in identifying anyone who said they were gay or lesbian as sinners,'' Hunt said. ``It was about who could shout the loudest.''

RECENT TARGETS

Keller can be just as volatile on television. Among his recent targets: Oprah Winfrey, whom Keller derided as a ''New Age witch,'' the Mormon Church and Florida Sen. Bill Nelson. When callers challenge him, he can get testy. During a recent live show, a young man named Danny from Boca Raton criticized him for manipulating people. Keller turned on him.

''When you die, what's going to happen to you, Danny?'' Keller asked, glaring intently at the camera.

''According to you, I'm probably going to Hell in a handbasket,'' Danny said.

''That's exactly correct, Danny. But you know what? You don't have to,'' Keller said. 'I'm on [TV] to reach people like you. 'Cause let me tell you something, the day you die and stand before God, you're not going to be able to whine and moan and cry and go, `Oh, nobody told me.' You've heard the story, you've heard the truth. According to God's word, your blood's not on my hands anymore, my friend.''

For viewers who take offense at his show, Keller is characteristically blunt: ``Last I checked, I didn't send somebody to your house to duct-tape you to a chair and put toothpicks in your eyelids to force you to watch the program.''