It is the fastest-growing form of Christianity in America. Some surveys say nearly 40% of Christians in this country describe themselves as "evangelical" or "born again." They are making their presence felt across the country. They flocked to see Mel Gibson's "The Passion of the Christ," making it one of the most profitable films ever released. And their conservative, strict interpretation of the Bible has set off fierce battles that threaten to tear apart mainline protestant congregations across the country. What does it mean to be an evangelical in America 2004 - and why is this brand of Christianity spreading so rapidly right now? Carol Marin investigates. watch