BOZEMAN, Mont. » As a girl, Danna Hopkins dreamed of having 20 children. Today, she and her husband, Brian, the pastor of an evangelical church here, are building a large family, but not in the way she imagined.

Hopkins gave birth to four children, now ages 7 to 11. Several years ago, inspired by compassion and a biblical mandate to aid "widows and orphans," the couple adopted two teenage boys and a young girl from Ethiopia. Then in 2012, they adopted another girl from Ethiopia.

Last year, when they read about dismal orphanages in the war-torn Democratic Republic of Congo, they started adoption proceedings for four young sisters whose parents, an agency said, had died of malaria and typhus.

"I believe it’s what God called us to do," said Danna Hopkins, 34.

She and her husband, and the Journey Church he pastors, are part of a fast-growing Christian movement that promotes adoption as a religious and moral calling — something evangelical theologians say every able Christian should consider. Its supporters say a surge in adoptions by avowed Christians has offered hope and middle-class lives to thousands of parentless or abandoned children from abroad and, increasingly, to foster children in the United States as well. Hundreds of churches have established new "orphan ministries" that send aid abroad and help prospective parents raise the tens of thousands of dollars needed to adopt.

The movement has also revived debate about ethical practices in intercountry adoptions, however, with charges that some parents and churches, in their zeal, have naively entered a field filled with pitfalls, especially in impoverished countries susceptible to corruption. These include the risk of falsified documents for children who have relatives able to care for them, shady middlemen out to profit and perhaps bribe officials, and even the willingness of poor parents to send a child to a promised land without understanding the permanence of adoption.

In March, in a pointed notice that sent shudders through adoption agencies and would-be parents, the State Department issued an alert about Congo. It warned that several children whose adoptions had already been approved by the Congolese government had been "taken from orphanages by a birth parent or relative," indicating that those children were not orphans eligible for American adoption in the first place.

The U.S. Embassy in Kinshasa said this month that it had stepped up its own investigations of prospective adoptions, resulting in delays of up to six months. The Hopkinses are now anxiously waiting for the Embassy to grant immigrant visas to the four girls who are legally their daughters.

In one milestone for the new movement, it was officially endorsed in 2009 by the Southern Baptist Convention, which called on churches to create a global "adoption culture" in response to "the horrors of a divorce culture, an abortion industry, and the global plagues of disease, starvation, and warfare."

Many of the adoptions involve couples, like the Hopkinses, who have biological children but see taking in others as a fulfilling response to global suffering.

"The orphan crisis is the greatest humanitarian issue in modern times," said Jodi Jackson Tucker, 51, of Durham, N.C. As their children left home, she and her husband adopted four children from Uganda over the past three years.

The presence of evangelical Christians is especially evident in intercountry adoptions, which have declined overall, to some 8,668 entering the United States in 2012, as more countries restrict or ban them because of scandals or politics.

Church officials and adoption experts say couples encouraged by the new Christian movement account for "a significant and growing minority of international adoptions," in the words of Adam Pertman, executive director of the Evan B. Donaldson Adoption Institute, a research group based in New York.

Critics of the movement include Kathryn Joyce, the author of a new book, "The Child Catchers: Rescue, Trafficking, and the New Gospel of Adoption" (Public Affairs, 2013), which charges that a "sense of mission has frequently obscured the harm" caused by a global "adoption industry."

David M. Smolin, director of Samford University’s Center for Children, Law, and Ethics in Alabama and an evangelical, said the new movement had often fallen into the same traps that led a succession of countries, including Guatemala, Cambodia, Vietnam and Nepal, to close down all foreign adoptions after baby-selling scandals.

"Now people are repeating the same mistakes in Uganda and the Democratic Republic of the Congo," he said.

Amanda Bennett, a Christian and a lawyer in Chicago, and her husband, had a heart-wrenching encounter with fraud in Congo last year. Through an American agency, they signed up to take three young siblings from an orphanage.

As they started the process, they began to see red flags: contradictory accounts about the family, indications that the mother was alive, the sudden firing of the Congolese orphanage director.

In August they flew to Kinshasa to investigate themselves and discovered that the fired director was the aunt of the children, whose mother and father in eastern Congo had other children at home.

In a bizarre clash of cultures, the Bennetts met in Kinshasa with relatives who said they were hoping that the three children would be taken to America, get educated and make money — eventually, perhaps, sending cash home or sponsoring other family members to emigrate.

The Bennetts withdrew, losing the $28,000 they had already given to the agency, and have joined with other misled parents to promote more intense scrutiny of African adoptions.

"It’s the biggest fear of adoptive parents — that there is family out there looking for the child," Bennett said. "I think people go into this with good hearts, but like many who go into the developing world and want to help, they don’t know how easy it is to hurt."

Leaders of the adoption movement respond that such lapses are uncommon and that the humanitarian need remains huge.

Jedd Medefind, president of the 9-year-old Christian Alliance for Orphans, said that the maturing movement was acting to prevent abuses and offer a broader response to vulnerable children.

Many panels at the alliance’s latest annual "summit," which was held in early May in a Baptist megachurch outside Nashville, Tenn., and attended by 2,500 people, focused on the need for churches to provide post-adoption support to families that are sometimes overwhelmed, particularly as more adopt older children with physical or emotional problems.

In their work abroad, he said, more American churches are supporting family preservation efforts and indigenous adoption. Rick Warren’s Saddleback Church in Southern California, for example, has won praise in Rwanda, a country hoping to close down orphanages, for working to reunite children with local relatives and aiding poor families.

At the Nashville meeting, Susan S. Jacobs, the State Department’s special adviser for children’s issues, said, "Our good intentions are not enough." Some of the problems, she said, have been eased by the Hague Convention, which mandates stronger scrutiny of children and adoptive parents. A number of countries, including Congo, have not signed it, though. Bill Blacquiere, president of Bethany Christian Services, told participants that, while serious lapses were rare, "as Christians we should be leading the fight for reforms." He condemned adoption-agency payments to orphanages that are tied to the number of children they refer, which "opens the door to trafficking."

Done properly, an adoption can seem like the advertised godsend. Silas Hopkins, now 18, arrived in Montana from Ethiopia after being abandoned, shining shoes in the streets.

When he first spotted Brian Hopkins, who was on a mission trip, through a window at the orphanage in Ethiopia, he told a friend, "Dude, that’s my Dad." The feeling proved mutual.

Four years later, Silas is doing well in high school and says he hopes one day to go back to Ethiopia "and do something cool" such as helping children find schooling and work.

Brian and Danna Hopkins beamed, but they are worried about the four Congolese girls they have not yet met.

Embassy officials in Kinshasa said they would be making a visit in late June to eastern Congo, the war-ravaged and dangerous region where the girls’ orphanage is.

The Hopkinses are flying to Kinshasa this weekend to urge the officials to investigate their daughters as soon as possible. "We don’t know the next time they will have permission to travel there," Danna Hopkins said of the Embassy staff. "It could be months."