Young men in baggy track suits linger around a gas station in Bonn. Rain drizzles. This is the meeting point for my interview with two Salafist preachers. A minute past 5 o'clock in the evening, a lone man arrives to pick me up.

"Yeah, we're radical," the man smiles. After a dramatic pause, the clean shaven 20-year-old adds: "radically on time." His smile turns into a grin. He does not shake my hand. "You have to understand," the man says. In western countries, not shaking someone's hand is considered an affront. But this man's strict interpretation of the Koran forbids him from offering me - a woman - his hand to shake.

The man explains that he will film the conversation with the preacher. "It's safer for you, and it's safer for us. But you probably don't want to be on camera at all, right?" The two preachers, who would like very much to be on camera, sit in a small café across from the gas station. We walk over. Turkish music plays from a loudspeaker. The older one, Ibrahim Abu Nagie, stirs his coffee while the younger of the two, Abu Dujana, plays with his white iPhone.

They offer me a friendly greeting and wave a waitress over: "Sister, another coffee, please."

Return to 'original' Islam

The two men are "Salafist preachers who are dangerous," a spokesperson for Germany's domestic security agency in North Rhine-Westphalia (NRW) told me prior to the interview. But an expert at the University of Osnabrück qualified that claim: Ultraorthodox, yes, but dangerous? "Not necessarily," says Elkaham Sukhni. He's a doctoral candidate at the Osnabrück Institute for Islamic Theology. Sukhni explains that Salafism is a very conservative movement, one which seeks a return to the early Islam from the days of the Prophet Mohammed.

"Later judgments and interpretations are rejected by Salafists," Sukhni says.

The preacher Ibrahim Abu Nagie calls it "the true Islam." But he identifies himself simply as a Muslim, rejecting the term Salafist as a concept used by the media and politicians to divide Muslims. Abu Dujana, the younger preacher, talks of a "planned agitation" by the media and politicians. "Zionist advisers" counseled the government to launch this campaign against Muslims, says Abu Nagie smiling. He left the Gaza Strip for Germany when he was 18 years old. In Gaza, he dreamed of Germany - of the technology and discipline.

"Now you're going to ask about Shariah," Abu Dujana says. He strokes his long, black beard, which could just as easily belong to a Cuban guerrilla. Abu Dujana is eloquent and educated - he points out that he's a registered student. Naturally, he would like to have Shariah in Germany, but that's not possible - not yet. Under Shariah, one doesn't just arbitrarily get their hand cut off, Abu Dujana says. There are rules and legal experts.

'We are observing with concern'

Germany's domestic security agency, the Federal Office for the Protection of the Constitution, estimates that there are some 3,800 Salafists in Germany. The Rhineland is home to around 1,000 of them, with a trend toward growth. Only a minority supports violence, but the transition from political activism to Jihadism and violent Salafism is fluid, according to the domestic security agency. "We are observing with concern," the agency's North Rhine-Westphalia branch says.

Violent Salafists are a "minority within a minority," emphasizes the Islam expert Elhakam Sukhni. Of all the groups within the Salafist scene, the violent factions are by far the smallest, he adds. There are also the ultraorthodox: "The women wear veils, and the men wear long robes." According to Sukhni, they hardly appear in public, because they have withdrawn into a parallel society. And finally there are also the groups around Abu Nagie and Abu Dujana, "who have become so conspicuous recently due to their missionary efforts."

Abu Nagie and Abu Dujana met each other at a mosque in the city of Frechen near Cologne. They've been missionaries for eight years now. They call it "da'wa," an invitation to Islam. Abu Nagie also talks about "marketing" or "charity." Initially, they distributed CDs of sermons, which they started uploading to the Internet. They also give away Korans and hold seminars - and have gained a following.

The Islam expert Sukhni has observed this trend: "For the first time sermons were held in German, in a simple and understandable language, and that was of course attractive."

Abu Nagie discusses the crisis hotline that he offers to young Muslims. Sometimes he receives up to 200 calls a day. From time to time, young Muslim girls call in, who do not want to participate in swimming class. He tells them to give their school principal a Koran and remain patient.

Attractive to young people

Why is Salafism attractive to young people? I climb the steps of an inconspicuous mosque in Bonn to find answers. A school girl, who is chatting with her friends, stands up and offers her hand to me. Salafists don't have a problem with two women shaking hands. "Are you a convert?" she asks me. She smiles softly. Worn, faded prayer rags form a kind of mosaic on the floor. The winter cold and the sound of passing cars drift in the room through the poorly insulated window.

"God willing, she will recognize the true religion," murmurs an older woman in Arabic to the young girls and gestures to me with her chin. The young girl nods, "God willing." The black garments that cover her body make her look older. She says it doesn't disturb her that people stare at her and that she sometimes has problems at school. She believes that God will reward her for her troubles.

"Above all, it's young people between 15 and 20 who get carried away by Salafism," says the Islam expert Sukhni.

The question of violence

Young Salafists often claim to know the absolute truth, Sukhni says. Of course there's the danger that a small minority among them advocates violence. Sukhni calls it "self-radicalization through the Internet," when young people let themselves get carried away by radical messages on YouTube, by al-Qaeda for example. Abu Nagie and Abu Dujana do not advocate violence. At worst, one could accuse them of not taking a clear enough position against violent factions.

Abu Dujana says that if he noticed that a young person was interested in violence, he would of course speak with that person. "It's not a taboo topic," the preacher adds. But young people who "have advanced" down the path toward violence wouldn't seek his counsel anyways, he says.

In May 2011, the right-wing group "Pro NRW" sought to provoke Rhineland Muslims by carrying caricatures of the Prophet Mohammed during a demonstration. Abu Dujana says he drove to his mosque to tell his congregants to remain calm.

"I said to the people, don't go out, don't let yourself be provoked," the preacher recounts.

Nevertheless, many Salafists took to the streets of Bonn for a counterdemonstration. Violence broke out with the police and an officer was stabbed by an alleged Salafist. The officer was severely injured and had to be hospitalized.

'Black sheep'

"Of course there are black sheep," Abu Dujana says. One can detect a hint of agitation in his voice. Every weekend during a soccer game or a demonstration by left-wing activists, there is violence, he says. But the Salafists are always being picked on, the preacher adds. He doesn't understand why politicians won't sit at a table and "talk with us." Abu Nagie shakes his head - no, he won't meet with politicians, not even Angela Merkel. "Unless she converts to Islam," he says. The others laugh.

Abu Dujana passes a Koran across the table: "It's for you, extra laminated." Abu Nagie smiles: "It's my great pleasure to offer you Allah's word." He gestures to his iPhone: the authorities are always eavesdropping on his conversations. But that doesn't disturb him. On the contrary, he says that it's "a lot of fun." Abu Nagie often talks about Allah's love on his cell phone, hoping that the authorities listening in will take it to heart. He is convinced that some of them have already converted to Islam.

Abu Nagie asks me before I leave if I want to bring a couple Korans back to the newsroom. He says he still has a couple of copies in his car that I am welcome to take with me.