DALLAS (Sept. 16, 2001)--Christians are saddled with Paul Hill, who murdered a doctor outside a Florida abortion clinic in 1994. Jews are burdened by Dr. Baruch Goldstein, who killed 29 people in a Hebron mosque the same year. And Muslims are shackled to Osama bin Laden.

All claimed to kill in the name of their God. And all are rejected by the mainstreams of their faith.

The tradition of mainstream Islam holds that Muslim individuals and nations are all involved in a sacred struggle--the jihad--to purify their hearts and act in accord with God's will. Sometimes the jihad is external, a battle generally defined as a war of self-defense.

But who is the enemy? And what kinds of force are justified? Extremists like bin Laden jump the track by rejecting centuries of Muslim theologians who have wrestled with these questions, many experts on Islam say.

Muslim leaders in this country and abroad--including some who are no friends of the United States--have lined up with powerful condemnations of Tuesday's attacks. U.S. law enforcement officials say they are still building their case against bin Laden and his followers. But many American Muslims say they fear that even the speculation has put their faith on trial.

Like the Bible, Islam's sacred texts frequently discuss battle and war. And like parts of the Bible, parts of Islam's texts justify fierce fighting against enemies. Judaism and Christianity have long traditions of interpretations that define a morally appropriate war. Islam has similar traditions that many Muslim scholars say have been perverted or ignored by Muslims who commit terror in the name of God.

"Anyone can prove anything from any scriptures, provided he has a two-dollar piece of equipment," said Jamal Badawi, head of the Canada-based Islamic Information Foundation. "That is enough to buy a cheap pair of scissors to cut up verses and put them together the way you want."

Most Americans understand Christianity and Judaism well enough to recognize the extremes of those religions. But despite the presence of as many as 6 million Muslims in this country, Islam is still a mystery for many Americans.

The image of Islam is not helped by news reports of Muslims--and even some Muslim clerics--who have been linked to terrorism. And some of the world's most infamous terror groups claim to be acting in the name of Islam: Islamic Jihad, Hamas (an acronym for Islamic Resistance Movement) and Gamaa al-Islamiya (the Islamic Group).

"I think they believe that what they are doing is religiously not just justified, but mandated," said Khaled Abou el Fadl, a professor of Islamic law at UCLA. "And they believe that they are sufficiently pure that they, rather than anybody else, represent Islam."

The vast majority of Muslims would disagree, he said.

The extremists represent a theology foreign to most of the 1.3 billion Muslims in the world, experts on Islam say. And even some Muslims who embrace the causes these groups fight for say extreme pro-terror beliefs represent the lunatic fringe of a puritanical, literalist branch of Islam whose influence has spread in the past 35 years.

The word "Islam" is derived from an Arabic word that means "peace." But mainstream Muslim theology differs from the Judeo-Christian perspectives most Americans are comfortable with. For instance, even mainstream Muslim scholars debate whether suicide bombers in Israel are religiously justified, Badawi said.

Suicide by itself is condemned in several texts. But death in righteous battle is praised, even if the soldier knows he will die. Some Muslim clerics butt heads over the definition of combatants. For example, some Muslim theologians who support the Palestinian cause say every Israeli adult is a potential soldier and therefore a suitable military target. Others dispute that analysis.

There is near-unanimous condemnation of attacks on children and the elderly, Badawi said. And Tuesday's attack is far outside any acceptable Islamic legal standard, he said.

Bin Laden, on the other hand, has declared that all Americans of any age are religiously suitable targets. That extremism is what pushes him and his followers far outside the mainstream, some experts on Islam say.

All Muslims trace the history of their faith to Mohammed, who died more than 1,300 years ago. Muslims revere him as God's greatest and final prophet. Muslim tradition holds that their holiest book, the Quran, was dictated to Mohammed by the angel Gabriel.

As is true for any sacred text, the Quran is filled with difficult and seemingly contradictory passages.

The Bible has its "eye for an eye" verse that some Christians struggle to reconcile with Jesus' command to "turn the other cheek." The Quran says in one verse that Muslims should take care not to transgress the limits of battle "because Allah does not love transgressors." Another verse says that enemies may be subject to execution, crucifixion, having hands and feet cut off, or exile.

Collected sayings of Mohammed, called hadiths, and other writings may reconcile some of the apparent conflicts. One says: "If people do good to you, do good to them; and if they mistreat you, still refrain from being unjust." Another story tells of Mohammed ordering his soldiers not to mistreat women and children, even during a battle. Both the Quran and hadiths offer examples of respect given to Christians and Jews--both considered along with Muslims as "people of the Book."