Two months into the captivity of Flavia Wagner, an aid worker with Samaritan's Purse, her Sudanese kidnappers let her give news to the outside world. Speaking on a satellite phone, Wagner told Agence France-Presse that she was living a "nightmare" and it was growing worse. The 20 men around her no longer gave her clean water to drink, she said, and she no longer felt safe: "They are threatening me, my life, my health."

At the Samaritan's Purse command center, the response team waited to hear more of her condition. Edward Densham, deputy response manager for the crisis, said everyone in the command center dropped what they were doing and gathered to pray for Wagner. That morning and afternoon as always, the staff of Samaritan's Purse prayed for her safe return.

Wagner endured more than three months of captivity before she was set free. She has hesitated to speak about her ordeal since her release, or the role her faith played in it, but Densham said faith was a "core value" for the people fighting to get her back. Samaritan's Purse requires each new hire to sign a Statement of Faith-in part so that shared faith unites them through crises like this one. A recent court case upheld relief organizations' freedom to hire only those who share their religion, but not all Christian relief organizations take advantage of it.

In Spencer v. World Vision, the 9th U.S. Circuit Court of Appeals sided with a Christian relief organization after it fired three employees who stopped avowing Christianity. World Vision requires its employees to sign either a statement of faith or the Apostle's Creed, and each employee provides a personal statement of faith during the hiring process. When World Vision found that three employees were holding alternative chapels, managers asked the employees to reaffirm their commitment to the Christian faith. They said they no longer believed in the deity of Christ or the Trinity, so World Vision fired them. The employees alleged discrimination and sued.

Title VII bans religious discrimination in hiring but allows an exemption for "a religious corporation, association, educational institution, or society." The dissenting judge narrowly interpreted this to mean a church or a place of worship while the other two judges gave two different criteria-a potentially troubling outcome for those hoping for clear agreement. The final criteria stated that in order to have religious-based hiring, an organization must self-identify as religious, do work that furthers those principles, and hold itself out to the public as religious.

But not all Christian relief organizations take advantage of the freedom to hire Christians. Catholic Relief Services, the international relief organization affiliated with the U.S. Conference of Catholic Bishops, says its mission is rooted in Catholic social teaching, but in hiring it picks applicants "on the basis of merit without regard to . . . religious beliefs." Feed the Children calls itself a "Christian, international, nonprofit relief organization" and an Equal Opportunity Employer that consider applicants "without regard to . . . religion."

In presenting itself to the public, Habitat for Humanity speaks of the "economics of Jesus" (the idea that God magnifies human efforts when we respond to human need) and the "theology of the hammer" (defined as the principle that acts of love can bridge theological differences). Because Habitat believes the "theology of the hammer" bridges religious divides, it has never had a religious hiring requirement.

On the other side of the spectrum, Compassion International lists "personal relationship with Jesus Christ" as a job qualification. A qualified candidate is a "consistent witness for Jesus Christ, maintains a courteous, Christ-like attitude" in interpersonal relations, and prays for the ministry.

For international organizations, a consistent hiring policy can become difficult. World Vision US hires only Christians, but its sister entity World Vision International makes exceptions for countries where the law forbids Christianity or for countries where it's difficult to find qualified Christian staff. Samaritan's Purse requires its American staff to sign the statement of faith, but in countries where persecution is a threat it does not require staff from those countries to sign.

Stanley Carlson-Thies, president of Institutional Religious Freedom Alliance, said religious organizations are often reluctant to declare that they only hire co-religionists. They may not know they're allowed to or they fear backlash from donors and activists. But they still unofficially screen candidates, perhaps by asking if they're comfortable attending required Bible study and prayer or asking if a candidate can affirm their mission. According to a Faith and Organizations Project report, very few religious organizations formally require employees to share their faith, but they still recruit by word of mouth in their faith network, advertise in their religion's media outlets, and make sure potential employees understand their values.