HABBANIYA CECE, Iraq  The last Christian man in town goes to church each morning to clean the building and to remember the past. Romel Hawal, 48, was born in this town in Anbar Province back when most of the population was Christian. Now, he said, his 11-year-old son knows no other Christians and has no memory of attending a church service.

“When my son swears, it is on the Koran, not the Bible,” Mr. Hawal lamented.

His wife wants to leave town or leave the country, joining what is becoming an exodus of Christians from Iraq and throughout the Middle East. But Mr. Hawal said he felt an obligation to stay. And he found support from an unlikely source.

“What gives me courage,” he said, “is that my Muslim brothers say, ‘Don’t leave.’ ”

Here in Habbaniya Cece, residents talk about their town as an oasis of ethnic and religious harmony, where Christians and Muslims, Arabs and Kurds, Sunnis and Shiites all lived together for decades without friction. On one short stretch of rutted road near Mr. Hawal’s church, Mary Queen of Peace, are an Assyrian church, a Sunni mosque, a Shiite mosque and another, older, Sunni mosque.

“This is the best place you will find in Iraq, because we have Christians and Muslims together,” said the mayor, Sabah Fawzi, a Muslim, who stopped by the church to look in on Mr. Hawal. “When my wife and daughters want something, sometimes they come to the church to ask God for it.”