A pagan religion that some experts say can be interpreted as encouraging violence is gaining popularity among prison inmates, one of whom is scheduled to be executed this week for killing a fellow prisoner at the foot of an altar.

Michael Lenz is scheduled to die Thursday for the death of Brent Parker, who was stabbed dozens of times at Augusta Correctional Center during a gathering of inmates devoted to Asatru, whose followers worship Norse gods. At his trial, Lenz testified that Parker had not been taking the religion seriously and had to die to protect the honor of the gods.

Other followers call the religion misunderstood and say most adherent inmates do not use it to further violent agendas.

Asatru has been gaining popularity among inmates, say religious leaders and prison experts who believe its roots in Viking mythology attract prisoners seeking power, protection and unity.

The gang culture in prison also contributes, said theologian Britt Minshall, a former police officer and Baltimore pastor who ministers to inmates. Some white inmates who felt threatened by black prison gangs formed their own gangs and sought out a belief system they felt would provide additional security, he said.

"It's a way of grouping together for safety," he said. "And you have to have a god in the middle of that to really keep you safe."

Asatru is often referred to as Odinism, although some followers believe the two are separate religions. It is a polytheistic, pre-Christian faith native to Scandinavia whose adherents worship gods including Thor and Odin.

It emphasizes a connection with one's ancestors and values honor, loyalty, generosity and truth.

An estimated 10,000 to 20,000 people in the United States consider themselves Asatruars or Odinists, said Stephen McNallen, director of the Asatru Folk Assembly, a leading Asatru group.

No national statistics are kept on how many inmates follow Asatru. But experts say its popularity enjoyed a boost from the Supreme Court, which last year sided with an Asatru inmate by upholding a federal law requiring state prisons to accommodate prisoners' religious affiliations.

Asatru is often associated with white supremacy, although most Asatru leaders bristle at suggestions of such a relationship.

A 1999 FBI report on domestic terrorism described Odinism as a "white supremacist ideology that lends itself to violence."

"What makes Odinists dangerous is the fact that many believe in the necessity of becoming martyrs for their cause," the report said.

Such comments are typical of those who don't understand Asatru, said Jane Ruck, who runs the National Prison Kindred Alliance and ministers to Asatru inmates. White supremacists make up only a small portion of Asatruars, and most inmates who follow the religion do not use it to push hate-filled, violent agendas, she said.

"There might be some white supremacists who consider themselves Asatruars, but they're not (Asatruars) because they're not following our beliefs," Ruck said. "We don't hate anybody; we just want to take pride in our heritage."

Lenz and another inmate, fellow Asatruar Jeffrey Remington, stabbed Parker a combined 68 times with makeshift knives. Remington was also sentenced to death but committed suicide in 2004.

According to Art Jipson, who studies white racial extremism and directs the University of Dayton's criminal justice studies program, Lenz's belief that fatal force was warranted is not surprising.

"If he believes the fight was necessary, whether or not it was legal is the least of his concerns," Jipson said. "If he's a truly devout practicing Odinist or Asatruist, he's doing what he must do. And it would be a shame — it would be a black mark on his soul, his spirit ... for him to be cowardly and not to fight."

That kind of warrior mentality can exacerbate the tense environment behind bars, said Mark Potok, a leader at the Southern Poverty Law Center in Montgomery, Ala., which monitors hate groups.

"It's a theology that celebrates raw physical power and domination, and that is why I think it is so popular among prison inmates," Potok said. "The kind of inmate who might be attracted to this is a white man who is looking for justification for extreme violence, who is looking for an ideology which explains why he should be the boss."