Ali Unsal pulled the table closer to his chair and opened the Koran, Islam's holy book. His friends, gathered in his simply furnished Fairfax living room, grew quiet, and their weekly Islamic study session began.

Unsal's reading from the book was followed by a discussion about religious sincerity. The three women and eight men then talked about the spiritual benefits of fasting to prepare for Ramadan, the Islamic holy month that begins tonight when the new, very thin crescent moon appears.

For these young professionals, all immigrants from Turkey, the regular gatherings are enriching. "It's kind of like brainstorming," said Zehra Turan, 34, of Fairfax City, a mother of two who is studying for her medical board exams. "Ten minds are looking from maybe 10 windows on the same subject. So we can see more sides. . . . It helps me feel more strongly about my faith."

Such sessions are common among Turkish Muslims who -- like the Fairfax group -- embrace the ideas of Fethullah Gulen, a Turkish mystic and scholar who teaches a moderate, outward-looking brand of Islam.

Gulen, 64, has been living in the United States for the past six years. A reclusive figure, he shuns interviews and television appearances. But in recent years, his outlook, which stresses modern life and Islamic spirituality, has gained a growing number of supporters in Turkey and among the Washington area's estimated 20,000 Turks.

He presents "a modern interpretation of Islam compatible with science, democracy and freedom," said Hasan Ali Yurtsever, 38, a research scholar in Georgetown University's mathematics department and a member of the study group.

"After 9/11, a lot of groups said they are moderate and changed their rhetoric," said Zeyno Baran, director of International Security and Energy Programs at the Nixon Center, a Washington think tank. "But the Gulen movement for the last 30 to 40 years has been saying the same thing. They have not changed their language because they want to be okay now."

Gulen's thought is heavily influenced by Sufism, the ancient mystical sect of Islam that emphasizes a personal religious experience of God as divine love.

In particular, the Gulen movement reveres the 13th century Sufi mystic and poet Jalal al-Din Rumi, who lived in Turkey. And Gulen serves as honorary chairman of the Rumi Forum, a Washington area group that promotes interfaith activities and such cultural events as recent performances in Washington and Norfolk of the Whirling Dervishes of Istanbul.

Whirling dance is a form of prayer for some Sufis. But nowadays, it is more a cultural expression of Sufi Islam, said Yurtsever, the forum's president.

In Turkey, the Gulen movement is a presence in hundreds of schools that follow a rigorous secular curriculum heavily weighted toward science. Religious instruction follows a government-approved syllabus or is nonexistent. Gulen followers in Turkey also run the daily newspaper Zaman, an Islamic-oriented television channel, radio stations and an Islamic bank.

Though nonpolitical, the movement is controversial in some Turkish quarters. Radical Islamists revile it, saying it is too open to Western ideas and other faiths, and many military officials and secular-oriented intellectuals worry that Gulen and his devotees secretly want to establish an Islamic state in Turkey.

Gulen has faced criminal charges several times of seeking to overthrow Turkey's established secular political order. The latest charges against him, made in 1999, were nullified after recent legal reforms there, according to scholars on Turkey, who say Gulen lives in the United States -- in Pennsylvania and New Jersey -- so he can be treated for a heart condition.

At Unsal's home in Fairfax, the guests came casually dressed and, following Turkish custom, left their shoes inside, at the front door.

The men and women mingled, and only one of the women wore a head scarf. The group included two businessmen, a schoolteacher and a historian. Gulen had written the essay they discussed on "Sincerity or Purity of Intention."

"Sincerity starts with the heart and then comes to your mouth and deeds," said Unsal, 33, who holds graduate degrees in theology and is publicity manager for the McLean-based American Turkish Friendship Association.

He urged his fellow Muslims "not to show off" and to keep their good works between themselves and God.

"Only God knows if you are sincere. There is no way to measure sincerity," added Ali Aslan, 38, Washington correspondent for Zaman.

"There is no sincere-o-meter," Yurtsever quipped, making everyone laugh.

With the formal discussion over, the group shared Turkish food and conversation.

Like others at the session, McLean resident Fatih Guner, 36, a bathroom-tile manufacturer, said he is eager for U.S residents to learn about Turkish Islam because of its tolerance.

"Gulen encourages Muslims to go to the West and show them what Islam is," said Aslan. "We are trying to be good role models."

Everyone in the group was looking forward to Ramadan.

Turan, who has been in the United States nine years, said she will decorate her home for Ramadan and have her children, ages 8 and 6, practice fasting for a few hours on weekends. She also will have them watch Turkish satellite television channels so they can see how Ramadan is celebrated in her native country.

"I'll try more to have them understand Ramadan as I understand it at home," she said.

The Whirling Dervishes of Istanbul perform the traditional Mevlevi Sufi ritual of whirling at the Warner Theatre. Whirling dance is a form of prayer for some Sufis but has recently become a cultural expression.The event was sponsored by followers of the Gulen movement, who are strongly influenced by Sufism.Sumeyye Yurtsever listens as her husband, Hasan Ali Yurtsever, talks before the performance. Hasan Ali Yurtsever said Gulen embraces a modern vision for Islam "compatible with science, democracy and freedom."