Atlanta ? It was a sign from above that the Christian book industry is changing.

Large banners reading “New York Times Best Seller” greeted bookstore owners and publishers at their industry’s annual convention in Atlanta.

The signs promoted “The Purpose-Driven Life” and “The Maker’s Diet” — just two of the Christian-perspective books that have successfully crossed over into the mainstream market in recent years.

Soaring sales have obviously meant greater profits for some, and publishers are keeping a sharp eye out for authors who have the potential to become the next best seller. But success has also meant greater competition for store owners, who can’t match the deep discounts offered by big retailers that now stock some Christian books.

So, many of the 11,000 people last week at the meeting of CBA International — a renamed version of the Christian Booksellers Assn., reflecting stores that offer more than books — were looking for their own niche.

Christian bookstores, a term generally referring to shops run by evangelical Protestants, will “never be able to sell as cheaply as Wal-Mart, Sam’s Club, Costco or Barnes & Noble,” said James Dion, a Chicago-based retail consultant. But they have a small advantage over those competitors — customer service and product knowledge, he said.

“The business is first and foremost a ministry. The good news: It’s a wonderful thing, it can become the most powerful customer service strategy you can develop,” Dion said. But store owners often “put business not even second, but third and fourth. They’re wonderful ministers but not really good businesspeople.”

Better marketing and merchandising is key, said Sherri Litza, owner of New Covenant Christian Supply in LaPorte, Ind. Sixty percent of the stores have less than $500,000 a year in sales, a relatively low figure, she said.

“We have to find a way to compete,” she said. “We have to develop our niche by customer service, customer loyalty and by becoming more efficient in what we do. All the stores are being challenged.”

AMY UMPHLETT, left, Christi Mize, center, and Julie Teal fill out surveys during the Christian Booksellers Assn. convention in Atlanta. Christian bookstores are looking for ways to compete with big retailers.

Gifts with a Christian motif are one niche, as is music, Dion said. Bookstores also are banking on sales of earlier books by now-popular authors, such as Jerry Jenkins and Tim LaHaye of “Left Behind” fame, along with Bible commentaries and works by established names such as prison evangelist Charles Colson and theologian Francis Schaefer.

Other stores are opting to open on Sundays — which, despite being the Christian day of rest, is a time they know their customer base will be out after church services and lunch.

Chuck Wallington, owner of Christian Supply in Spartanburg, S.C., said he’s seen more customers looking for some of the older titles. He’s also worked to grow his church supply business, selling communion plates, tithe envelopes, church bulletins and coloring books for Sunday School classes.

“When you connect with the churches, you tend to connect with people in the churches,” he said.