Nashville, Tenn. ? As a Roman Catholic missionary in the Islamic nation of Mauritania, Sister Claire Rheaume discussed her faith only with close friends and never made the sign of the cross before meals at restaurants.

The government of the north African nation allowed missionaries to discuss their beliefs, but the nun thought it was important to be discreet.

“It wasn’t denying your faith. It’s the respect that you have for the country,” said Rheaume, who spent 15 years in Mauritania and now works in Waltham, Mass.

Missionaries like Rheaume face a daunting challenge: how to share their faith without violating the laws and customs of their host nation. The case of American aid workers Dayna Curry and Heather Mercer, jailed then freed in Afghanistan, has prompted debate about the right approach.

“Churches have to be aware that they are guests of other countries,” said Kathleen Flake, a professor of American religious history at the Vanderbilt University Divinity School in Nashville. “Just like people who come to our country, we expect them to obey the law. So also other countries seem to have a reasonable expectation that we would obey their laws.”

Curry and Mercer were jailed on suspicion of breaking a Taliban law that barred them from preaching Christianity. After they were rescued in November, the women publicly acknowledged that they partially broke the law by showing a video about Jesus to an Afghan family.

Rheaume fears the pair’s actions will fuel suspicion of missionaries in Muslim countries and make it difficult for them to do their work. Even those intending to share only goodwill, not their faith, may run into trouble, Flake said.

“Common sense kind of tells you this will set everybody on edge,” Flake said. “To the extent other countries are suspicious of our motives, they will be more suspicious.”

Degrees of aggression

In their missionary training program at Antioch Community Church in Waco, Tex., the American aid workers were encouraged to “share how the Lord has changed their lives” as part of their work overseas, pastor Jimmy Seibert said.

Curry, a Nashville native, and Mercer, of Vienna, Va., then went to work in Afghanistan for Shelter Now International, a Christian organization based in Germany. In Afghanistan, discussing religion is simply part of the culture, and declining to do so could be offensive, said Udo Stolte, Shelter Now director.

“If you’re in Afghanistan, you’re invited to speak about your family and to speak about your profession, and they ask you to speak about your faith. I cannot tell them, ‘Don’t tell them who you are,'” Stolte said.

Other missionary organizations are more aggressive.

The Southern Baptist Convention’s International Mission Board the world’s largest Protestant mission organization with 5,100 missionaries in 185 countries encourages its workers to convert people, board spokesman Mark Kelly said.

The board was reorganized four years ago to direct more money and personnel toward the countries where most Muslims live. The board also publishes a guide for Southern Baptists on how to help Muslims accept Jesus Christ as their savior.

‘Presence as witness’

The U.S. Catholic Mission Assn., an umbrella organization for 650 groups that send 3,800 missionaries abroad, takes a more subtle approach.

Missionaries are told they can preach in countries where it is permitted or can show the virtue of their faith by quietly doing health, education and relief work, said Sister Rosanne Rustemeyer, the association’s executive director.

“We really believe that God uses our presence as witness,” she said.

J. Dudley Woodberry, professor of Islamic studies at Fuller Theological Seminary in Pasadena, Calif., also thinks Christians working in Muslim nations should be discreet.

Aid workers and missionaries should share their faith only with close friends or those struggling with extraordinarily difficult circumstances, such as the loss of a loved one, he said. Even addressing good-natured curiosity about Christianity can be dangerous, he said.

“It varies considerably from country to country, and it varies within the same country because there’s sort of a fuzzy line between proselytizing and just being a friend answering questions,” Woodberry said.