"Tongues was seen as a sign of the imminent second coming ofChrist," explained Synan, dean of the School of Divinity at RegentUniversity in Virginia Beach, Va. "Pentecostals felt a tremendousurgency to go out and convert the world before the second coming."

Nowadays, the missionary work, at first just aimed at Christianconversion, has evolved into church-building efforts. One of the largestchurches is an Assemblies of God congregation in Seoul, South Korea,which claims to have 730,000 members.

Synan said although Pentecostals seek converts to Christianity andnot Pentecostalism in particular, they believe the gifts of the spiritcan influence potential converts.

"They feel that the gifts of the Spirit help you evangelize," hesaid. "When people are healed miraculously that draws people to theLord."

Some of the most well-known faith healers, Benny Hinn and ReinhardBonnke, draw huge crowds to their crusades in the United States andabroad.

Brother Jeffrey Gros, associate director of ecumenical andinterreligious affairs for the National Conference of Catholic Bishops,has worked with Pentecostals and charismatics on both scholarly andgrass-roots levels. He has watched non-Pentecostals advance fromsnickering at so-called "holy rollers" -- for their unusual worshipstyle -- to realizing the charismatic version of Christianity is asauthentic as others.

"There is a way in which the differences are so great and yet thereis a kind of sympathy that has developed where people have gotten toknow each other," he said. As the movement has grown, it has influenced other churches and madeinroads into secular culture. Music written by Pentecostals -- such asJack Hayford's "Majesty" -- and expressive worship, such as the liftingof hands heavenward, has spread to churches without charismatic orPentecostal leanings. Best-selling author and Pentecostal preacher T.D.Jakes of Dallas recently partnered with Hallmark Cards for a new "LooseYour Spirit" line in the Mahogany brand of African-American greetingcards. Pentecostals also have reached high political ranks in Latin Americaand in the United States, including Attorney General John Ashcroft.

"Because of their numbers and the vigor of the movement, you'll seepoliticians rising up like Ashcroft and still there were a lot ofquestions and prejudices against him because of his faith," Synan said.

Even as it has had success in both the spiritual and secularsectors, the movement also has had its share of scandals, most notablythe sex and money troubles of televangelists Jim Bakker and JimmySwaggart in the 1980s.

"There were spectacular failures but despite that the heart of themovement continued to grow," said Synan said. "The big challenge afterone whole century is to keep the fires burning into the next century."