Whatever the outcome of the war in Iraq, Christians in that country are fearful about their future.

They worry that if Saddam Hussein's government is ousted quickly and new leadership put into place, the new government will follow the model of many Muslim countries and outlaw all forms of non-Islamic worship. The country's half-million or more Christians have been allowed to worship freely under Hussein and for generations have worked and lived comfortably with Muslims.

Christians also are concerned about a scenario in which warfare continues for weeks in such cities as Baghdad and Basra. They believe that their sanctuaries might become the targets of bombing attacks by Muslims, as occurred in Pakistan after U.S. troops invaded Afghanistan.

"You have some mullahs denouncing the Crusaders and the infidels from the minaret, meaning us Christians here," Bishop Shlemon Warduni of the Chaldean (Eastern Rite Catholic) Church said recently from Baghdad. "The fanatics in Iraq are using it as an excuse to act against the Christians."

Still another fear looms over Christian communities in Iraq, one that involves a threat posed by fellow Christians rather than by Muslims, say religious leaders and officials from faith-based humanitarian organizations in the area.

"There's concern that Christian [aid] organizations, many of them gathering on the border in Amman, [Jordan], will descend like a flock of vultures" in an effort to convert Muslims to Christianity, said Jim Jennings, founder of Conscience International, an independent humanitarian group specializing in medical care that has worked in Iraq for more than a decade.

Jennings talked of the "comfort" level, even a sense of protection, that Iraqi Christians felt before the war started two weeks ago. Hussein, a secular leader who has appointed Christians to senior-level positions -- including his second in command, Deputy Prime Minister Tariq Aziz, a Chaldean -- after the 1991 war offered government support to religious groups.

Shiite Muslims, who had mounted an unsuccessful revolt against Hussein's rule in the wake of the 1991 war, were given funds to repair mosques. And churches, ranging from Catholic and Protestant to Pentecostal and Orthodox, received free water and electricity and assurances that they could worship freely -- as long as they did not proselytize.

Such a relatively open religious environment is nearly unheard of in many Muslim countries, where practicing any religion but Islam can bring imprisonment or, in some cases, death. Some of those countries, such as Saudi Arabia, are allies of the United States. Last month, the Saudi defense minister restated his government's prohibition against Christian worship and denounced critics who argued that churches should be allowed.

"There are no churches -- not in the past, the present or future," he said. "Whoever said that must shut up and be ashamed."

Many churches in Iraq, some of which trace their lineage to the 4th century, have long operated humanitarian outreach programs independent of international assistance. Outside financial help for a specific congregation or religious group is outlawed by the current Iraqi government.

If a victory by the U.S.-led coalition is followed by a surge in outside aid from overtly religious organizations, it would upset a cultural balance in Iraq that has existed for generations, said Michael Porter, head of the Middle East region of the Silver Spring-based Seventh-day Adventist Church.

Most dangerous are well-intentioned Christians who come with bread in one hand and a New Testament in the other, Porter said in a telephone interview from his office in Nicosia, Cyprus.

Some evangelical aid organizations, including the Rev. Franklin Graham's Samaritan's Purse, have said they have workers ready to enter Iraq with food, emergency shelter and medical supplies for its predominantly Muslim population. Unlike faith-based aid organizations that provide emergency assistance without proselytizing, Samaritan's Purse does both.

"Since 1970, Samaritan's Purse has helped meet needs of people who are victims of war, poverty, natural disasters, disease, and famine with the purpose of sharing God's love through His Son, Jesus Christ," the organization says on its Web site under the heading "mission."

Porter calls such intentions a "total disconnect" in Muslim countries. "Christians doing evangelism in an Islamic country is like going down Pennsylvania Avenue trying to sell Communism," he said.

The most effective purveyors of different religious views could be Iraqi exiles who, if the Hussein regime is overthrown, will return from the United States and other countries with a broadened view of religious freedom, said Bill Stuart, who works with missionaries to the Middle East through Brooks Avenue Church of Christ in Raleigh, N.C.

One of those exiles, who was imprisoned and tortured by Hussein's government during the Gulf War and later fled the country, has trained for Christian ministry while in the United States and plans to return when the situation allows, Stuart said. The man asked not to be identified for fear of causing harm to his relatives, many of whom still live in Iraq. Jennings, a Southern Baptist, said Atlanta-based Conscience International -- founded in 1991 after the war -- has taught more than 500 medical workers in Iraq techniques for saving the lives of sick children in low-tech hospitals. It also has provided assistance in Afghanistan and other countries, with funding from a range of Christian, Muslim and Jewish groups.

Speaking from a hotel in Amman, Jennings expressed concern that some Christian aid groups poised to enter Iraq from Jordan have no sense of the delicately balanced culture they might soon enter with "an American invasion mentality."

Jennings said he's not opposed to religious groups sharing their faith to those who ask about it -- and many Iraqis will, he said, out of sheer curiosity about religion.

"You can do marvelous work and have a marvelous witness, but not if you come in behind a conquering army and think you're going to do a mass distribution of aid and religious literature, then skip the country and leave the [indigenous] Christian community to suffer the consequences," he said.

Despite anxieties about U.S. and British bombing near residential neighborhoods in Baghdad, many Christians there continue to worship, Porter said. He said services at the Adventist church in Baghdad were held as scheduled last Saturday, the Adventist Sabbath, and were expected to continue today.

Last week, before telephone communication was lost, a church member spoke with her sister in Cyprus. "We're getting used to the bombing and know that God is in control," she said. "Don't worry too much about us."

With Baghdad's church of the Virgin Mary in the foreground, smoke billows from burning trenches of oil. As the battlefront approached the capital, many church services still went on.

Despite fears about bombing, services at the Seventh-day Adventist church in Baghdad were held as scheduled last Saturday, the Adventist Sabbath. Iraqi children at Syrian Orthodox Church in Mosul.An entry plaque, below, marks the Assyrian Presbyterian Church in Baghdad. Under Iraqi President Saddam Hussein, Christians have been allowed to worship freely. Several Iraqi officials, including Deputy Prime Minister Tariq Aziz, are Christians. Aziz is a member of the Chaldean, or Eastern Rite Catholic, Church.