For Conservative Muslims, Goal of Isolation a Challenge

"For example, if you go home and watch TV every day . . . that's not going to help you get close to God," he says in one lecture. "If you go out to the game . . . or if you go to the movies often, if you love to go to parties, if you love music -- all these things are not going to bring you closer to Allah."

Also forbidden by Islam, Khan teaches, are "love letters, or chatting in the chat room without the presence of a guardian, . . . or writing e-mails that you know you have no business writing."

Young Muslims in particular must be aware of the dangers to their faith, Khan says, because youth "is the time when there are a lot of temptations . . . when all these Ivy League universities try to take you to brainwash you into the way they want you to grow up, the way they want you to think." It is the time "that all of America, all of the West, tries to concentrate on you . . . because once they control you, . . . then they have you, and for the rest of your life, you think like them."

Khan believes that Islamic schools are imperative because Muslim children "now are not equipped to deal with mainstream America without compromising their Islamic values." Usually, he says, "a big mixture happens between mainstream America and mainstream Islam, and . . . in most cases . . . Islam loses."

He stresses how Muslims are different from non-Muslims, whom he calls "unbelievers." Citing the mistreatment of Muslims, he says, "we must come together so we can ward off all these attacks." Khan adds that by an Islamic community, he means "we begin to buy houses and begin to live right around the [mosque] so we meet each other" during the five daily prayer sessions.

In the hostile environment cited by Khan, Dar-us-Salaam offers a comforting alternative. The congregation has a "real community feel, so a lot of young people are attracted," said Irfaan Nooruddin, 25, of Silver Spring, a financial analyst who is not a member but sometimes prays there. "I don't agree with their Salafi [outlook] at all. But I do respect the fact that they're people who are attempting to understand the religion."

Mostafiz Chowdhury said he chose Al-Huda, the congregation's school, because he wants to provide his children with an "Islamic upbringing" and protect them from public-school ills such as drugs and "having free sex."

Ultimately, if American Muslims continue to feel embattled, Salafism itself could become more attractive. When moderate Muslim groups that promote integration feel they are under scrutiny or discredited by the government, said Najam Haider, an adjunct professor of Islamic studies at Georgetown University, "Muslims turn societally inward, and that turning inward gives Salafism more influence because Salafis aren't saying we need to integrate."

What they offer, Haider added, is an alternative: "Muslim identity that is separate from America, grounded in Islamic history, a very demarcated community of Muslims. Those are very separate from American values in a lot of ways."

Staff writer Mary Beth Sheridan and news researcher Karl Evanzz contributed to this report.