The New York Times claimed last year that Christian relief and development agency Samaritan's Purse blurred the line between church and state by using U.S. Agency for International Development grants to "preach, pray, and seek converts" in El Salvador.

The organization responded that in its aid work, federal funds exclusively pay for building materials and supplies—not evangelism. But Samaritan's Purse did not deny its efforts to "preach, pray, and seek converts."

Instead, as it has since its founding 32 years ago, the organization clearly stated its motivation: the love of God. Says Mark DeMoss, spokesman for president Franklin Graham, "We are going to tell people what we do and why we do it."

This clarity of purpose—and the open presentation of it—is one key way Christian organizations remain true to their original vision.

"As an institution grows and the founders move on, an organization becomes more professional and more influential," says David Beckman, president of the ecumenical lobbying group Bread for the World and a Lutheran minister. "In the course of that growth, it is relevant to ask, 'As we evolve, are we staying consistent with the original vision?' "

Many groups maintain their vision through Bible studies, prayer, and worship. At World Vision, a weekly chapel service is "probably the most important thing we do," says Serge Duss, director of public policy and government relations. "There, we constantly affirm to each other to follow Christ where he wants us to go. We are all led here to do this work."

Employees at Bread for the World have started their own prayer and study groups during lunch hours or before work. Board meetings also include devotions and prayer. Says Beckman: "It is a very powerful religious experience ...