Ms. Yousef, the worshipper in Baghdad, said lingering fear pushed her to send her son to live with relatives in Arizona last year. She said she was arranging for her daughter and other son to emigrate.
“There’s still fear here, and there’s no stability in this country,” she said.
Iraqi officials have made efforts to secure churches since the violence of 2010.
High blast walls topped with wire netting and barbed wire surrounded the St. Joseph Church in Baghdad in the middle-class district of Karradeh. Blue-khaki-clad Iraqi police guarded roads surrounding the church and checked papers of passers-by as worshippers filtered inside.
Four Iraqi Christian volunteers, two men and two women, stood at the church entrance, double-checking people entering.
White-robed church volunteers marched down the church aisle behind Father Sirop, who waved incense and chanted in the white-painted church adorned with three ornate chandeliers and a series of simple paintings illustrating the life of Christ.
Worshippers stood for lengthy passages of Father Sirop’s Mass, at one point bursting into applause when he told them: “Celebrate! You are Christians!”
• Diaa Hadid reported from Baghdad.