CORAL SPRINGS, Fla. -

More than 7,000 people flock to Church by the Glades every weekend.

"Probably key to our success or growth -- we have amazing people volunteering," said Pastor David Hughes.

From parking to nursery duty, thousands work for free at the church. Piph Oszeus drives two hours a day to volunteer.

"I say 50 [hours a week]," he said.

Laurie Kelliher volunteers in the administrative office for 30 hours a week.

"They've done a lot for me, and I wanted to do something for them," she said.

"We'd be dead in the water without our volunteers," added Hughes.

Other megachurches, including Potential Church in Cooper City and Calvary Chapel in Fort Lauderdale, also have thousands of volunteers. And, those volunteers recruit others to visit and join them.

"We just try to find a way to tap into our communities and be the hands and feet of Jesus really and see how we can impact the communities and also bring them to church," said Oszeus.

Hughes said the church has always been big.

"If you go to the Bible, in Acts chapter 2, the church starts in day number one, they go from 120 people to 3,000," he said. "The church has been a big church in the Bible."

Oszeus admitted feeling apprehensive about getting lost in the crowd.

"At first, it was big, but once I got here, it became small because the church was so open and welcoming," he said. "Quickly, I was able to know everybody -- everybody's name -- and the church became very, very, very small."

Critics compare the megachurch movement to large chain stores arriving and driving out small businesses. Hughes said he doesn't plan to expand, but if more come, they'll have to be accommodated.

"I'm ambitious but it's a sanctified ambition," he said. "It's an ambition for God and his kingdom, not mine."

Despite the growth of megachurches, a recent study says overall church attendance on a typical Sunday is down nearly 20 percent within the last decade.