HOUSTON — An arena that basketball fans once packed to see the NBA's Houston Rockets is about to take on a new role — home to the largest congregation in the nation.

Lakewood Church, led by televangelist and best-selling author Joel Osteen, has grown so much in recent years that this weekend it will expand into a new building: the former Compaq Center.

The arena was home to the Rockets when they won two league titles in the 1990s and the Houston Comets of the WNBA when they won four. It now seems fitting that "discover the champion in you" has long been the church's slogan.

"It all ties in together," Osteen says. "Many sports champions have been crowned there and we believe we can crown champions in life."

Lakewood, a nondenominational Christian church, recently became the first congregation in the country with an average weekly attendance of more than 30,000 for its services — and had an average attendance of 32,500 in the first quarter of this year, said John Vaughan of Church Growth Today, an organization that studies megachurches, based in Bolivar, Mo.

Now the Lakewood Church Central Campus will seat 16,000 people, about twice the capacity of its current sanctuary, with parking spaces outside for 8,000 vehicles.

With more elbow room, Lakewood will now reduce its weekend English language services from four to three, though it will continue a weekly Spanish language service.

Critics have sometimes taken Osteen to task for downplaying the sinful nature of humanity and the need for repentance. An article this week in the liberal Protestant magazine The Christian Century calls Osteen an "easy theological target" who turns the language of the Scriptures "into a vague religiosity, or into more digestible categories of self-help and self-improvement."

But there's no denying his success. Lakewood, which first opened in an abandoned Houston feed store in 1959, has grown almost fivefold since Osteen took over the church in 1999, shortly before the death of his father, former pastor John Osteen.

The facility, which took 15 months and about $75 million to complete, features two waterfalls, three gargantuan TV screens and a lighting system that rivals those found at rock concerts. Two choir lofts with 12 rows of rich purple pews sit between the waterfalls, accented by live foliage.

Absent, however, is a cross, an image of God or Jesus Christ or any other traditional religious symbols.

Osteen said his father never displayed such symbols and he simply continued the tradition. Instead, the new location will feature a larger version of the church's trademark globe, rotating slowly behind Osteen as he preaches.

As big as the Compaq Center was, it wasn't big enough, and five stories were added on. "Obviously, we needed more room and that is kind of funny," Lakewood spokesman Don Iloff said.

Along with classrooms, the addition includes a chapel, a baptismal area, meeting space for young adults and an entire floor dedicated to the church's television broadcast efforts.

Osteen is viewed by more people than any other preacher in the United States, according to Nielsen Media Research. He is seen nationwide on cable networks including Daystar, USA, Discovery, ABC Family, PAX and Black Entertainment Television. He also is seen in more than 100 countries.

His book, "Your Best Life Now: 7 Steps to Living Your Full Potential" has sold almost 3 million copies and has been on The New York Times' best seller list since its October release. The book was so successful that the 42-year-old pastor — who did not go to seminary and never preached a sermon until a week before his father's death — refused his six-figure church salary this year.

In response to critics of Osteen's motivational, easygoing approach, his mother, Dodie Osteen said: "We don't preach the gospel sad, we preach it glad."

One church member also brushed off the criticism.

"I don't care what the critics say," said Grace Kiarie, a 32-year-old pharmacist and three-year member of the church who is originally from Kenya. "Pastor Joel gives me enough word to make it from 12:15 on Sunday to 10:45 the next Sunday. He gives me practical ways to live my life."

Kiarie, who is black, said she was drawn to Lakewood because of its diverse congregation. The Osteens tout the church as one of the most diverse in the country with an almost equal mix of whites, blacks and Hispanics.

"This is what heaven should be like," Kiarie said. "It is often said that Sunday at 11 a.m. is the most segregated time of the week, but it's not that way here. They've done an amazing thing here to bring black, white, Hispanic and all kinds of people together. It doesn't matter here. You forget about color."

Osteen and his wife, Victoria, said the church's new location, will lend itself to even more growth, noting that an estimated 180,000 cars pass by each day. "There's an opportunity to be able to reach so many more people," Victoria Osteen said.

Osteen said his vision is to one day preach to 100,000 people each weekend, and Vaughan believes the church will be packed from the start.

Today's opening, scheduled to be televised live on Daystar, will feature a short address from Texas Gov. Rick Perry and a televised message from former Rockets coach Rudy Tomjanovich.

Osteen has said that when a church reaches 80 percent capacity it's time to start looking for a new place. But where do you go when you're already holding services in a converted basketball arena?

One day, joked Osteen's sister, Lisa Comes, "Joel will say 'Well, I guess we've got to move to the (60,000-seat) Astrodome now.' "