On a Saturday night in early December, it's business as usual on downtown Tempe's Mill Avenue. Dreadlocked buskers beat on bongos across from a head shop called Hippie Gypsy, banging over the strains of Jimi Hendrix's guitar on "All Along the Watchtower" screaming from the store's speakers. The scent of patchouli fades into the reek of horse manure into the sugary coffee smells of Dunkin' Donuts as people shuffle down the street, below brawny frat guys in ASU jerseys beating their chests and bellowing from the balcony of Hooters.

Beneath the neon glow of Hooters, a large crowd has gathered at the intersection of Fifth Street and Mill, looking up at the restaurant's TVs, all tuned to the Oscar De La Hoya vs. Manny Pacquiao fight. Even the cops have stopped to watch.

But there's another distraction in the street. Among the shoppers, street musicians, club-goers, and college kids, there's this wispy hipster guy holding up a sign as large as the plasma TVs. Dressed in a vintage, blue velvet Dolce & Gabbana blazer, black-and-white vinyl loafers, and a black silk tie with a double Windsor knot, he looks like the lovechild of an Anthony Burgess novel and an Andy Warhol film.

He's carrying a white megaphone and wearing a shiny silver-metal backpack that resembles a vacuum cleaner — an example of the "industrial design" he loves so much.

A couple of people ask if he's going to "fire up the jetpack" and fly away.

But more ask about the big, black sign that reads "Damn God America" in gold block letters.

Usually, street preachers share the word of God. For the past several years on Mill, you haven't been able to walk from one bar to another without tripping over someone sharing the love of Christ through an amplifier or a stack of Bible tracts.

But this blue velvet guy is a different kind of preacher. He's a devout non-believer, and he preaches atheism.

The smiling man with the sign is Omar Call, a 31-year-old fashion designer and salesman of high-end blue jeans. No matter the jibes, he maintains the dignified look on his face, helped by his high-cut Peruvian cheekbones and prominent, Roman nose. Strands of thin, dark hair hang from his English golf cap and in front of both ears, like pointed sideburns.

He asks people what they think his sign means.

One guy says it's anti-American. Another says it's communist. A third says it's blasphemous. Call explains that the sign means, "America, damn the idea of God. Damn the religious dogma that dictates and destroys."

Some of the passersby give him dirty looks; a few flip him off and call him names.

Call has been coming to Mill Avenue every Saturday for the past three years to get flipped off, but also to have heady conversations. He particularly relishes debating the Christian street preachers who've sermonized on this strip for close to a decade. He thinks it's fun. The first time he did it, he says, he went home afterwards and "it was like I was on a high. I was so excited."

On quiet nights, he stands with his signs on the street and waits for people to ask questions. Having "logical, rational" discussions and making people think is almost like a creative art project for him.

In the beginning, his tactics were deliberately provocative — he dressed as Jehovah and stood on the corner, holding a sign that read, "I quit." When preachers set up speakers and started barking about damnation, Call would talk back through a bullhorn.

Other atheists, particularly those from an ASU group called the Secular Free Thought Society, often join Call on the corner. Initially, the group was small — a few atheist ASU grads bringing out their own tracts to counteract the Christians who handed out "$1 million bills" with Bible scriptures on the back.

But the SFTS has grown, and ever since it got two microphones, a loudspeaker, and a "background soundtrack" playlist on the iPod with themed songs like Roger Waters' "What God Wants" and Black Sabbath's "War Pigs," it's started to look more like a chaotic club party on the corner of Fifth and Mill than the satirical-but-serious piece of art Call says he's performing.

The Christians on Mill clearly view him as a thorn in the side. To the other atheists on Mill, he's a god of the godless. But he doesn't care to hang with either group. With his stylish wardrobe, bookworm intellect, and theatrical approach, Call just doesn't seem to fit in anywhere.

And he seems to like it that way. His "heroes" run the gamut, from Ayn Rand and Sir Isaac Newton to Adam Carolla and Richard Cheese. Ask him to describe himself, and Call will give you a laundry list of ten-dollar words, some self-invented: bi-furious, serotonic, lethological, pantagruelist. But one word he'll never use again is Mormon.

Some of the Christians tell a story about Omar Call, which he doesn't dispute. There's no video of it, but it goes something like this.

One Saturday night this past summer, Call gave one of his favorite demonstrations on Mill Avenue. He placed a penny on the ground, and started yelling at the nearby Christians through a megaphone.

"You say you have faith," Call told them. "The Bible says that if you have the faith of a mustard seed, you can move mountains."

"So if you have even this much faith," he continued, pinching his thumb and forefinger together to illustrate the size of a tiny mustard seed, "You should be able to move this penny with your faith. Can anybody move this penny even a centimeter with the power of their faith?"

The Christians looked at Call, then down at the penny. Nobody said anything. The penny didn't move.

"Come on!" Call prodded. "If faith the size of a mustard seed can move a mountain, why can't your immense faith move this little penny? If anybody can move this penny with the power of their faith, then I will believe!"

Jim Coleman listened to Call's argument, shaking his head. Coleman's 83, and he's been coming down to Mill Avenue to hand out church tracts for the past eight years. He was the first Christian to start hanging out down here, and he's well liked.

He's got a jolly, grandfatherly demeanor and never yells at anyone, preferring to take a humorous approach to evangelizing. Rather than assail readers with scriptures about eternal damnation, the tracts Coleman hands out are filled with cute little jokes like, "If at first you don't succeed, don't try skydiving" and "Nothing is foolproof to a sufficiently talented fool."

Coleman says he was completely paralyzed eight years ago, and though he's regained some use of his legs, he walks only with great difficulty. It's easier for him to use a wheelchair.

On this night, Call tried to use Coleman's disability to belittle his faith.

"If you have the faith of the mustard seed, you'll be healed," Call told the old man. "Get up! Walk! Be healed! Don't you have faith?"

Call later apologized to Coleman for the incident but says he doesn't remember much about it now except that it did happen. He admits that wasn't one of his finer moments, but he says he tries to be respectful. If he seems harsh sometimes, he says, it's because he's just so driven on his mission to question Christianity. But the man who now stands on Mill with a "Damn God America" sign was once on a different mission.

If he could go back in time 10 years, Call would have the fiercest theological debate of his life — with himself. Back then, he was a devout Mormon missionary, born into and blessed by the LDS church in Baltimore, with ancestors on his father's side that he says go all the way back to the church's foundation. He's read the Book of Mormon several times over. He's read the Bible from beginning to end. He's read most of the Oxford English Dictionary. He learned Hebrew so he could read the Old Testament in its original language. He knows the scriptures well.

"I was a believer. I believed in Christ," Call says. "I have testimony of the gospel of Jesus Christ and that I was saved to live with him in glory forever."

But about seven years ago, things began to change. Call lost his faith, and found passionate anger toward religion in its place. He officially left the church his parents had raised him in and announced his atheism to them on (of all days) Easter, upsetting his family and making subsequent holidays really awkward. Then he started coming down to Mill Avenue every Saturday night. The Secular Free Thought Society atheists followed but have gone from being brothers in arms to a cramp in Call's style.

Call often works Mill with his good friend Jimmy Curley, a Ph.D. candidate in neurolinguistic programming he met as an undergrad. Like Call, Curley insists on dressing well when he anti-preaches, and he's been with Call since his first night protesting preachers on Mill. But aside from Curley's companionship, this atheist is a loner. He doesn't want to hang out with his would-be disciples on Mill, and the people closest to him — like his wife of six years, Amina — aren't particularly interested in his anti-God rants.

Amina spends her Saturday nights at home with friends. (Sometimes Curley's wife calls, and they hang out.) But she understands her husband's need for a public platform on his views, and accepts it because he enjoys it so much. She was with him the night he went down to Mill and saw preachers screaming into microphones for the first time, and remembers how furious he was about it. He told Amina (they met in college; she grew up without any organized religion) the Mill Avenue evangelists had no right to yell at people and call them sinners, that somebody should stand up to them.

So he went home that night and ordered a bullhorn on eBay.

"The opportunity to serve a mission is indeed both a privilege and an honor, one that I have been looking forward to and preparing for my entire life. Seeking to share the word of the Gospel with other children of Heavenly Father is certainly one of the most worthwhile and far-reaching endeavors an individual could hope to strive to embark upon."

Omar Call wrote these words in his Missionary Call Acceptance letter to the LDS church in 1995. He was excited, though going on a mission was entirely expected.

His father, Brad, is a medical doctor and a former missionary himself. He met Omar's mother, Lola (now a psychologist), while on his mission in Peru and converted her to Mormonism. Lola was a devout Catholic and in her late teens at the time, and after she converted to Mormonism, she left her predominantly Catholic home country to attend Brigham Young University in Utah.

Back in the U.S. himself, Brad heard Lola was at BYU and called to see how she was doing. They began dating and eventually married. They had two children — Omar, born in 1977, and his sister, Ariana, born 15 months later. When Omar was 6, his family moved from Baltimore to Tucson. They continued attending three-hour Sunday services at an LDS church.

Ariana, who lives in Tucson and works as a high school science teacher, says their home environment was "somewhat restrictive," but otherwise normal. Halloween was a big holiday for the family, and they all made intricate costumes, especially Omar. One year, he and Ariana made Garbage Pail Kids outfits by cutting the bottoms out of garbage pails, slipping trash bags over their bodies and climbing into the pails, and rigging the lids to open so their heads could pop out.

Another year, Omar made a Transformer costume out of cardboard boxes and metallic paint, with elaborate robot limbs on the front, and an automobile coming out the back. The last Halloween Omar's father recalls him "dressing up" was when he was 14. He dressed as himself, and said he had the most original costume anywhere.

Their mother didn't want Ariana and Omar to watch too much TV, so she taught them how to sew and paid them to do it several hours every week. Today, Omar alters clothing for customers at the boutique where he works and sews his own fashion designs — sometimes well into the night and early mornings.

His whole life, Omar says, he followed the tenets of his religion closely. He attended every church service, refused to listen to secular music on Sundays, didn't watch R-rated movies, abstained from premarital sex, and tried not to drink any caffeine. At 19, he says he was quite secure in his faith, to the point of being "self-righteous."

In 1995, Call enrolled at Arizona State University, planning to follow in his father's footsteps as a physician. Before he got more than a year deep in college, the LDS church sent him on a mission to Lisbon, Portugal.

Call's schedule as a missionary was typically rigid: He got up at 6 a.m. every day, prayed, showered, dressed in his suit, went through the neighborhoods of Lisbon and knocked on doors all day, and went to bed by 10:30.

The goal was to spread the vitally important message of God to as many unconverted souls as possible.

It was hard for him to accept rejection. Once, Call was trying to find a neighborhood in Lisbon where he could "share the gospel." As a senior companion, he was in charge of guiding the younger missionaries, and every day, they would try to find some sort of divine guidance for the Lisbon area.

"Every day, we were like, 'Okay, there's somebody that the Lord wants us to teach. There's someone who wants to hear the gospel. We have to be faithful enough that we can be led by the Holy Spirit to find them,'" Call says.

So they got down on their knees and prayed, asking God to guide them to the right place. Afterward, they looked at a map and had a really strong feeling about one particular neighborhood. So they went there, and they had a bad day.

"We went and knocked on doors for eight hours — the whole day," Call recalls. "We couldn't get anybody. People slammed doors in our faces. No one let us in."

They returned to one particular door, practically pleading to be let in. "I was getting kind of desperate at this point," Call says. "I thought, 'Something's wrong. I thought this was the area; this is where we were led. There's someone here we need to teach.'"

The woman who answered the door told the missionaries to stop begging her, and closed the door. Call wandered off so his junior companions wouldn't see him crying, and spent the next several days thinking about what had happened.

"Eventually, I was able to assuage my conflict with it by just saying, 'This was a test to see if I'd be able to maintain my devotion in the face of rejection. The Lord just wanted to see if I would stay strong,'" Call says.

Toward the end of Omar's work in Portugal, the president of his mission wrote a note to his parents. In it, President and Sister Clegg thank Brother and Sister Call "for sharing with us such a dedicated and spiritually prepared son . . . We loved Elder Call. He is one of our savior's finest missionaries."

"This is stingray skin," Omar Call says, holding up a beige belt adorned with glittery turquoise patches and sparkling studs.

The patches are dyed scales, and the rest of the belt is leather, he explains. The belt is by Robbie French. The belt is sleek, stylish, and costs $231 at 50 percent off.

It's noon on a sunny but brisk Wednesday in December, and Call is at work, showing some of the merchandise at Scottsdale Jean Company in north Scottsdale, where he's been selling high-end, designer clothing for the past 15 months. The wife of Poison singer Bret Michaels shops here all the time, Call says, along with a lot of athletes whose names he doesn't know. But he thinks he's seen Steve Nash here.

Though he abhors television and has no interest in sports (he prefers to read — no fiction, and always two books at a time), Call's done well as a high-fashion sales associate, selling shiny $200 shirts and $300 rhinestoned jeans to Scottsdale socialites. He's also interested in fashion design and has a room in his Tempe house, which he calls "Omar's Dungeon," filled with clothes, boxes of fabric, and his five sewing machines.

A few years ago, he designed a line of dresses and tops for the Scottsdale fashionistas who ran LabelHorde, and he recently made some silk-screened T-shirts. One shirt depicts Mickey Mouse with a goathead pentagram for his head, and the other bears a Louis Vuitton logo, modified to read "eViL." He says he'd like to focus on building up his own fashion line and, ultimately, make his living as a designer.

Call's work history is as chameleonic as his religious un-revival. Before he got into clothing sales, he worked as a loan officer for Centex Home Equity. When the loan industry began to tank, he got a job making dresses for a company called Artistry in Motion. He did that for a year before landing the gig at Scottsdale Jean Company. Years earlier, when he'd returned from his mission, he got his first "real job" at a car dealership — to pay off the 1994 Isuzu Trooper he'd just bought there — and sold cars for four years while earning a degree in business and design from ASU.

Throughout college, Call remained active in the Mormon Church, graduating from the LDS Institute and teaching gospel doctrine in the singles ward at ASU. He fervently studied various world religions, including the history of Christianity and Judaism.

"The church always said, 'Don't learn too much. Don't try to know everything,'" Call says, smirking.

That, as it turned out, was the turning point for Call. The more he learned, the less he believed.

"What I learned in church about the history of the church, it wasn't the same as what actually happened," he continues. "We can't say that God is the same forever in his church, whether it's Mormonism or Christianity, because if God never changes and he's omnipotent and omniscient, why would he say one thing one time and then change his mind and say something else? It didn't make sense to me."

Call started to think that maybe God was not the "One Great Truth." Maybe God did not even exist. "I came to a point where I said, 'I'm really not an agnostic. I believe that there is no God, as I was taught,'" he says.

He changed his mind about his major at ASU, too — from microbiology to bioengineering to linguistics to anthropology to calculus before finally landing on an interdisciplinary degree in design and business. He was still pre-med when he met a pretty blond coed named Amina in his organic chemistry class.

Amina says she was "born to hippie parents," not raised with any religion besides the golden rule, really. She was a good girl, but she certainly wasn't Mormon and had no interest in converting. She was going through a breakup when Call started lurking in her lab group, seemingly bored with his. Amina was impressed with his intelligence and confidence, and shortly after breaking it off with her beau, she started dating Call.

For four years, Call hid their relationship from his parents, who always referred to Amina as "Omar's friend" when she visited on holidays. Then on Christmas in 2001, Call's mother sat him down asked him what his intentions with Amina were, and if he was going to marry her.

To his own surprise, he answered yes.

"Having fallen in love and dated this non-member, the idea of marriage — I didn't know how to wrap my head around it," Call says. "I loved her, but I didn't have the belief anymore. I never found a Mormon girl who met me at the same level of conviction, yet who was interesting and intelligent. So when my mother asked me if I was going to marry her, for the first time I thought, 'Yeah, I'm gonna marry this girl.'"

The two were married in a small, non-denominational ceremony in Sedona the following May. Unbeknownst to his family, Call had met with his bishop the week before the wedding and requested that his name be removed from the LDS church records.

Nevertheless, he and Amina planned to continue attending church; she'd agreed to accompany him to one Sunday service a week. They went the first two Sundays after their wedding ceremony. On the third Sunday, the alarm went off and Amina asked Call if they were going to get up and go to church.

He rolled over and said, "Nah. Let's sleep in."

Easter Sunday 2007 was a dramatic day for the Call family.

Call's parents were visiting his sister in Tucson. Omar and Amina joined them, and the whole family went out to see what he calls "a pretty avant-garde" Easter play called The Last Days of Judas Iscariot that "had some nudity and cursing in it." They knew the play was going to be unorthodox, but didn't realize how much. The play took place at an inconspicuous art gallery/performance space off Congress Street. Call doesn't remember the name of the venue, but he does remember that the theme of the play was "honesty versus loyalty."

Afterward, Call took his already-jarred parents and his sister out for ice cream. He asked his parents what was more important — honesty or loyalty. His mother said both were equally important. His father said he believed honesty was more important than loyalty.

Call said he agreed with his father, and on that note, over waffle cones and sprinkles, he announced that he'd had his name removed from the LDS church records.

His mother was devastated. "I wish you'd never told me this," her son recalls her saying. "Why did you do this?"

Call says that, to this day, they've never discussed it again. They get together on holidays and talk about everything else.

"My mother's father was a military man — very stoic, and an atheist," he says. "Sometimes I think my mother's devotion to religion is a rebellion against her father's atheism. My mom once said to me, 'I'm not going to let your atheism destroy this family the way it did mine!'"

Call's admission that he was an atheist was difficult for his family to accept, but his compulsion to publicly and skillfully debate preachers on Mill doesn't surprise them. When he and Jimmy Curley started coming down to Mill to debate, Call says, he approached it with the same zeal he showed as a Mormon missionary, and he hasn't lost it yet. What he has lost enthusiasm for is the Secular Free Thought Society always being on the same corner he's on.

It started with a few SFTS members handing out their own tracts on Mill, which said things like "Is this your God?" and quoted the Bible story, from the book of Kings, in which God sends bears to eat small children who mocked the prophet Elisha. Call found the tracts amusing and was happy to meet people who shared his views. But then the SFTS started bringing a microphone and more members, each one adamant about bringing his or her own philosophies to the debates.

Now things are getting out of control. On a recent Saturday night, a discussion between Call and the Christians disintegrated into anarchy when some of the atheists screamed at the preachers about how creationism is a lie and grabbed at Call's microphone. The mic ended up being commandeered by an inebriated blond woman who was just passing by. She then was provoked by the excited crowd to deliver an impromptu, slurred sermon.

The Friday after the incident, Call and Jimmy Curley — both dressed in suits and ties — sat down with SFTS founder Shawn Esplin in front of the Slices pizza joint, off Mill. Call had been in front of the post office earlier with his "RIP GOD" sign, and the SFTS was hanging out behind him in jeans and black T-shirts, eating Dunkin' Donuts and blasting the music of black-metal band Dimmu Borgir through a speaker. Nobody would approach Call, and when somebody finally did, a couple of SFTS members stood in front of his sign and talked over him.

Call explains to Esplin that he moved because "my message was being diluted." He and Curley clarify that they're not members of the SFTS. They say they're doing their own thing, but they'd like for the group to be more effective. They should dress so that they appear respectable and approachable, have a couple people on each corner instead of one big gaggle, and respect other people enough to not talk over them or shout.

Esplin agrees with most of the points, but says he's not sure what to do. What's important to him, he says, is that there are voices opposing the Christians on Mill, and that the SFTS brings as many people around to "their side" as they can.

"Maybe we should figure out why we all come down here and what we're trying to accomplish," he says, pushing his glasses up the bridge of his nose.

Curley explains that he and Call aren't trying to convert people to atheism; all they want is to make people think, to have respectful and stimulating discussions when they come down to Mill.

"Every night is like a one-night stand," Curley says. "We come down here, onnight only, and some nights the performances are better than others, but you don't expect it to be more than what it is."

"It doesn't have to mean anything," Call adds. "We whore out our ideas and interact with bystanders. We're intellectual prostitutes. Or pimps."

Esplin giggles nervously, shifts uncomfortably, and tugs on the collar of his flannel shirt.

A city bus coughs out a cloud of exhaust on Call's corduroy pants, and then there's a woman wagging her finger in his face. It's another Saturday night in mid-December and Call's getting another earful about his "Damn God America" sign.

A family of five — a father, a little boy, two young girls, and the finger-wagging mother — are making their way down the strip when they see the sign and stop. The mother leans in closer and narrows her eyes, then takes a big stride toward Call.

"God's done a lot of good in this world!" she says, her cheeks flushed with fury. "You shouldn't talk about God that way and be doing destructive things like this!"

Call calmly says that he doesn't believe God exists. The little boy takes his father's hand and asks, "Well, then, who created us?"

"Nobody had to create you," Call tells the kid.

The little boy, who looks to be about 7, shouts, "Read the Bible!"

"I've read the Bible," Call says. "If God exists, where is he?"

The mother scowls and points to her chest. "God is in our hearts."

As the family stomps off, one of the little girls, who can't be much older than 5, turns, raises her fist in the air, and passionately yells at Call: "Damn you!"

Though he's shocked by the little girl's parting comment, Call laughs it off. He's used to people getting angry. His wife and friends think his activism is amusing because they know his sense of humor, but they do worry for his safety sometimes. He's had people get in his face and yell. He's had drinks thrown on him.

In the end, Call says, his message is a simple one: Goodness can be godless. "If we had no religion but we could be moral, there is no contradiction there," he says. "If we could just relax as far as the doctrine and just acknowledge that we're all human beings and we should respect one another, we should love one another, we should help one another — these are Biblical teachings, but they're teachings known throughout the world. Treat others as you want to be treated. This is not rocket science. It's not so hard to figure out."

But some folks need more prodding. Omar Call is happy to oblige.

After being damned by the 5-year-old girl, Call works his way back to Borders, where a young woman in a black hoodie inquires about his "RIP GOD" sign. A small but curious crowd has formed around him. Rocking forth slightly on his heels, with a warm smile on his face, Call gives his favorite answer: "I think the concept of God has outlived its usefulness. It's time to put it out of its misery."

The woman takes a drag off her cigarette and says she disagrees. She believes in God. Call says he used to believe in God, too. She asks what happened, and the debate is on.