BOB ABERNETHY anchor: A special report today -- an update on megachurches, the huge evangelical, often nondenominational, Protestant places of worship with 2,000 or more members. Their numbers have doubled in the last five years from 600 to 1,200 nationwide. And now, more and more, a single church may become a megachurch by having branches at several locations. Judy Valente reports.

UNIDENTIFIED PASTOR #1: I want you to shout out as we begin to worship our God today.

JUDY VALENTE: Willow Creek Community Church outside Chicago -- the stereotypical megachurch, one of the oldest and best known. Twenty-thousand people attend the various services each week.

UNIDENTIFIED WOMAN #1: Good morning, New Life Community Church.

VALENTE: Some 20 miles away, in Chicago, New Life Community Church. This congregation itself is small, but it's only one of several worship sites that New Life has around the city. Total membership is 2,500.

VOICE OF UNIDENTIFIED PASTOR #2: Good morning, New Life Community Church! How are you guys going this morning? Are you guys ready to worship the Lord?

VALENTE: Multi-site congregations like New Life are growing. The main church, with services in both English and Spanish, is housed in what used to be a manufacturing plant on the city's southwest side. New Life has gone from this one location to eight locations in just the past five years. Each site has its own pastor.

Reverend JOHN PALMIERI (Pastor, New Life Community Church): There'll be churches that are struggling, going through difficulty, the doors are almost ready to close, and they'll touch bases with us -- this has happened in the past -- and say, "Hey, can you do ministry here?"

VALENTE: Megachurches today are not necessarily what they have long been portrayed as -- huge campuses, a homogeneous congregation packed with political conservatives seeking an entertaining form of worship and largely unconcerned with the community around them.

They come in all sizes and shapes, and the megachurch phenomenon shows no sign of slowing down.

Dr. SCOTT THUMMA (Hartford Institute for Religion Research): Americans are getting much more comfortable with thinking of religion in this super-size, in this large scale.

VALENTE: In a survey by the Hartford Institute for Religion Research, Scott Thumma, who specializes in the study of megachurches, found that the most widely held beliefs about them "could not be further from the truth."

Bishop T.D. JAKES (Preaching): And the preachers and the leaders of religious institutions lift up holy heads and call on the name of our God.

VALENTE: Dynamic, visionary pastors remain a driving force in megachurches. In Chicago, the goal of New Life Church founder Mark Jobe is to bring in one percent of Chicago's population -- 30,000 people.

A key factor in megachurch growth is the ability to respond to changes in public taste, for example, in music or manner of preaching -- in part because the largest percentage of them are nondenominational. Most have changed their worship style over the years.

Dr. THUMMA: An independent, nondenominational congregation can invent itself, in a way. A Southern Baptist church has to follow some traditions, or specifically United Methodist or Presbyterian church has to follow a very clear form of organization and worship style.

VALENTE: These congregations have become more racially and ethnically diverse than before, partly because of their sheer size and partly because they have made an effort to be so. The Hartford Institute estimates one-third of these worshippers are people getting established in a new community. Another third are coming from no faith tradition, and a third have come from other faith traditions or smaller congregations.

UNIDENTIFIED WOMAN #2: I was just reaching out for comfort, where I wasn't getting comforted at my church.

From Church Play: UNIDENTIFIED ACTRESS: Why don't you go sit?

From Church Play: UNIDENTIFIED ACTOR: Me?

From Church Play: UNIDENTIFIED ACTRESS: Yeah. You don't have to say anything, just sit.

VALENTE: Brief dramatic presentations are a way that some congregations have tried to draw their worshippers into the message. Critics have branded services like this "Christianity-lite." But Scott Thumma disagrees.

Dr. THUMMA: When you begin to look at what these congregations teach, you find a very rich, a very orthodox, and a very serious Christianity that requires considerable commitment on the part of the attenders.

UNIDENTIFIED PASTOR #3 (at pastors' meeting): So let's just kind of run through some of the points here.

VALENTE: On Monday mornings, pastors from the eight New Life worship sites meet to plan the subject of the next week's sermon. They are young. Some are not ordained but have been promoted through the ranks of the worshippers. The upcoming sermons will contain a single idea delivered as each pastor sees fit.

Rev. PALMIERI: We don't just come out with a canned sermon and regurgitate it on a Sunday morning. We add our own flavor, our own personality, our own passion to those messages. So it could sound different, but it's the same message.

UNIDENTIFIED PASTOR #3 (to congregation): Whatever else you're reading in the Bible, let me encourage you the next two weeks [to] read John, chapter four. Read it everyday, and you'll be amazed at how much better you understand it.

VALENTE (to UNIDENTIFIED MAN #3): What have you found here that's spiritually nourishing for you?

UNIDENTIFIED MAN #3: It's real. It's not fake. They take the Bible for the Bible. They don't make anything up. And it's really -- I feel confident when I come here, I know when the pastor's going to open up the book he's going to read from the book, and I feel confident that he's reading God's word.

UNIDENTIFIED MAN #4 (at Bible study): We just want to keep praying for the couples who are in our lives, who obviously need, you know, they just -- they just need Jesus, you know.