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

The organization responded that federal funds are used exclusively to pay for building materials and supplies in its aid work—not for evangelism. But Samaritan's Purse didn't deny it tries to "preach, pray, and seek converts." Instead, as it has since its founding 32 years ago, the organization clearly stated the motivation behind its work: the love of God. Said Mark DeMoss, spokesperson for president Franklin Graham, "We are going to tell people what we do and why we do it."

This approach doesn't apply only to federal funds. When inviting corporate sponsorships for its annual Operation Christmas Child, Samaritan's Purse openly acknowledges that the heart of the program is spreading the gospel. "We won't send a packet B that doesn't mention God in order to get more money," DeMoss told Christianity Today. "It might mean fewer corporate sponsors, but it is a matter of integrity."

This clarity of purpose—and the open presentation of it—is a key component for Christian organizations that have expanded their reach beyond the walls of the church but remain true to their original vision.

"As an institution grows and the founders move on, an organization becomes more professional and more influential," said David Beckman, president of 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?'"

Some organizations—such as The Salvation Army and Habitat for Humanity—have ...