For more than a century, three little letters have said it all.
"VBS. You mention those three and it draws people in. You don't even have to say anything else," said Ronnie James, the children's pastor at Millbrook Baptist Church. "It's a staple. Vacation Bible school is one of those things that every year, regardless of the size of the church, people look forward to."
James was the host for 300 youths at his Aiken church in June.
With roots dating back to the 1800s, summer Bible school is an enduring tradition that has received a number of makeovers, yet fundamentally remain the same.
"What we're seeing now are more churches doing VBS and doing it well," said Michael Chanley, the executive director of the International Network of Children's Ministry, a nonprofit that offers training and resources to children's pastors.
Enrollment in VBS programs in Southern Baptist churches alone topped 2.75 million youths last year, according to a 2010 count by LifeWay Christian Resources.
More than 82,000 of those young people professed faith in Christ last year as a result of a VBS program.
That's the chief aim of VBS programs, which also work to identify the "unchurched" of the community and to encourage the children and their families to participate.
"It's the best way we know to reach people," said Danielle Cox, a school teacher who coordinated VBS for 70 kids at Lakemont Presbyterian Church in Augusta last month. "Statistically, it's the age group you want to reach. Most people who come to know Christ accept him before they're 11 years old."
For decades, VBS have relied on a tried-and-true formula, said James, who has taught at Millbrook for three years, but worked in children's ministry for more than 20.
"The elements are pretty much the same," he said. "You have your Bible story, which is the main part, the recreation time, and the snack time. You have a craft. It's a formula that works."
This week, Millbrook's sanctuary was decorated with gigantic plastic-foam cutouts of the New York City skyline to match the the Big Apple Adventure theme.
It's one of several curricula created by LifeWay Christian Resources, an agency of the Southern Baptist Convention.
LifeWay has produced VBS resources since 1925, said Jerry Wooley, the organization's VBS ministry specialist. By the mid 1990s, curricula took a major turn, influencing the way thousands of churches plan and present VBS programs.
For the first time, LifeWay began developing themes that would "permeate every aspect of experience including, Bible study, music, mission studies, crafts, recreation, snacks and decorations," Wooley said.
Each is designed to reflect that summer's central verse and idea.
Children's ministry is more effective as a result, said Ginger Custer, the director of children's ministry at Abilene Baptist Church, where she has worked with children since 1992.
"When everything relates, you're creating an experience for the children," said Custer, who was host of her church's VBS for 290 youths in early June. "The fun, the excitement of it, the joy they felt is something they never forget. Kids this year are still talking to me about last year. They remember, and that is key."
Themes are a natural fit at larger churches with active VBS programs, but the development of themes has been especially key for smaller churches. Themes offer resource-starved churches a creative, comprehensive plan for the week, Chanley said.
"There's a reason they're so popular," he said.
VBS programs are, on the whole, getting sleeker, more relational, service-oriented and tech-savvy. The shift in VBS, however, isn't just happening in resource-heavy mega churches.
"There have been revolutions in VBS," said Chanley, who is based in Louisville, Ky., where he attends the 26,000-member Southeast Christian Church. "It'll continue being a trend. It'll just look different. In some places, a traditional VBS doesn't cut it anymore."
At Millbrook, organizers are making their summer programs more outwardly focused for a generation of kids looking to make an impact in their communities.
Kids in fifth through seventh grade attended VBX, a service-oriented program with a youthful name meant to play off the original VBS. The aim is to get the older youths in the community working on projects. About 50 participated this year, in addition to the 300 enrolled in the church's VBS for 3-year-olds through fourth-graders.
Even the younger boys and girls found a way to serve by competing to bring in coins, which will be donated to missionaries building a house in Mexico.
They're some of the ways in which VBS is changing shape for new generations while still covering fundamentals of faith, James said.
"Our biggest goal is always pointing boys and girls to Jesus Christ. We want them to know who he is," James said. "There are some boys and girls who have not heard of Jesus. We lay it out there."
After a presentation of the Gospel, children are invited to speak with volunteers and ask questions.
"We give everyone the opportunity but we won't force them," he said.
Increasingly, pastors say, VBS provides an opportunity for evangelism that is more relational than in decades past.
In the 1990s, LifeWay redesigned its program so that the primary evangelistic lesson would be scheduled on the third day of the program. Wooley said that is to "give time for relationships to be established and grow" before its teachers present the ABCs -- admit, believe and confess -- of becoming a Christian.
"We encourage teachers to present the Gospel everyday, but especially during the third session," he said."
At Lakemont, the church tracks and celebrates each child who professes faith in Christ. Last year, out of 74 enrolled in VBS, there were seven or eight children, Cox said.
'The goal is to introduce them to Jesus as the one and only way to heaven," she said. "If we're not doing that, I don't know why we're here."