By Dan Gilgoff, CNN.com Religion Editor

(CNN) - Given initial suspicions that Friday's bombing and mass shooting in Norway were carried out by Islamic militants linked to al Qaeda, the way police ended up describing the suspect behind the attacks came as a big surprise even to many security experts: The alleged attacker was called a "Christian fundamentalist."

But experts on European politics and religion say that the Christian fundamentalist label could overstate the extent to which the suspect, Anders Behring Breivik - who has told authorities that he carried out the attacks - was motivated by religion, and the extent to which he is tied to a broader religious movement.

"It is true that he sees himself as a crusader and some sort of Templar knight," said Marcus Buck, a political science professor at Norway's University of Tromso, referring to an online manifesto that Breivik appears to have authored and which draws inspiration from medieval Christian crusaders.

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"But he doesn't seem to have any insight into Christian theology or any ideas of how the Christian faith should play any role in Norwegian or European society," Buck wrote in an email message. "His links to Christianity are much more based on being against Islam and what he perceives of as 'cultural Marxism.'"

From what the 1,500-page manifesto says, Breivik appears to have been motivated more by an extreme loathing of European multiculturalism that has accompanied rapid immigration from the developing world, and of the European Union's growing powers, than by Christianity.

"My impression is that Christianity is used more as a vehicle to unjustly assign some religious moral weight," to his political views, said Anders Romarheim, a fellow at the Norwegian Institute for Defence Studies. "It is a signifier of Western culture and values, which is what they pretend to defend."

"I would say they are more anti-Islam than pro-Christian," Romarheim said in reference to what appear to be Breivik's views.

The manifesto is religion-obsessed in that it rants for long stretches against Muslims and their growing presence in Europe.

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It calls for a European civil war to overthrow governments, end multiculturalism and execute "cultural Marxists." The manifesto includes a link to a video asserting that the majority of Europe's population will be Muslim by 2050 "unless we manage to defeat the ruling Multiculturalist Alliance."

The author of the document identifies himself as Breivik, but CNN could not independently verify that he wrote the document, and Norwegian authorities would not confirm that the man in their custody wrote the manifesto, saying it was part of their investigation

Opposition to booming Muslim immigration to Europe, exacerbated by high birth rates in the Muslim community, has become a mainstay of Europe's burgeoning far-right, helping right-wing parties gain seats in parliaments across the continent.

But those right-wing movements are mostly secular. Europe's hard right does not have deep ties to Christianity in the way that the United States' conservative movement is entwined with evangelical Christianity and other theologically conservative religious movements.

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Recently adopted European laws aimed at curbing Islam's public visibility, including France's new burqa ban and Switzerland ban on minarets - towers that a part of mosques - were secular causes, not ones championed by Christian interests. Many Christian groups oppose such bans.

"The bulk of the anti-Muslim sentiment is not against Muslims as such, but is a secular rejection of how some Muslims allegedly want to place Islam at the center of society," Buck said. "It is more anti-religious than anti-Muslim."

Breivik's apparent manifesto, by contrast, cites biblical verses to justify violence for political ends.

"Clearly, this is not a pacifist God we serve," it says. "It's God who teaches our hands to war and our fingers to fight. Over and over again throughout the Old Testament, His people are commanded to fight with the best weapons available to them at that time."

"The biggest threat to Europe is the cultural Marxist/multiculturalist political doctrine of 'extreme egalitarian emotionalism,'" the manifesto goes on. "This type of political stance involves destroying Christendom, the Church, our European cultures and identities and opening up our borders to Islamic colonization."

The video that's linked to in the manifesto also includes some religious language: "Celebrate us, the martyrs of the conservative revolution, for we will soon dine in the Kingdom of Heaven."

Experts on religion in Europe said those faith-infused views are likely peculiar to the suspected gunman and do not appear reflect wider religious movements, even as they echoes grievances of Europe's right-wing political groups.

"He was a flaky extremist who might as well have claimed to be fighting for the honor of Hogwarts as for the cause of Christ," said Philip Jenkins, a Pennsylvania State University professor who studies global religion and politics, describing the suspected Norway attacker. "He did not represent a religious movement. ... People should not follow that Christian fundamentalist red herring."

At the same time, Breivik told investigators during interviews that he belongs to an international order, The Knights Templar, according to Norwegian newspaper VG, which cited unnamed sources.

He described the organization as an armed Christian order, fighting to rid the West of Islamic suppression, the newspaper said. He also told investigators he had been in contact with like-minded individuals and said he counts himself as a representative of this order, it said.

For many in Norway, the potential implications of the suspected killer's religion are still settling in.

"This is the first time we've heard of Christianity/religion as a driving force behind right-wing extremism," Buck said. "The mainstream right-wing movements in the Nordic countries (very small and disorganized groups in Norway) would generally point to the Old Norse beliefs, if anything."

"Norwegian, Nordic and European society," he said, "were totally unprepared for a violent attack from someone who calls himself Christian."