CARY - For Cary Christian Academy graduate Bobby Duncan, a powerful memory carries him into the new world: the moment the commencement speaker started singing "Mighty to Save" and the graduating class spontaneously joined in.

The song became the theme for the Class of 2011 during its service trip this year to Costa Rica, where students visited an orphanage and helped victims of a mudslide.

"The words really hit us and it speaks to us," said Duncan, senior class president.

The Christian song, performed by Rueben Morgan, an Australian pastor, focuses on compassion, kindness and faith.

Duncan, a National Merit Scholar, plans to attend the U.S. Naval Academy. He wants to become an engineer.

"No one in my family is in the military," he said. "I want to do a lot for my country, because it's done a lot for me."

He reports at the end of June.

"I think most seniors who graduate high school are a little bit scared. I'm really excited to find out what God is going to do with me and all my classmates."

Katrina Wertz, the class salutatorian, said the mission trip was special.

"We got to give them hope. Because we saw the looks on their faces, we could see God for real," she said. "One of my favorite things, is [classmates] started opening up. It's not a cliche to us when we say we have 56 brothers and sisters."

Wertz, who has scoliosis, plans to go to UNC-Chapel Hill to study neuroscience.

As the recipient of a Morehead-Cain scholarship, Wertz will get free tuition and spend 30 days this summer in Alaska.

"We're about to go into the world and we have enormous opportunity to reach people and serve people, so let's not waste the opportunity," she said.