On a recent night around 37,000 people packed into U.S. Cellular Field, home of the Chicago White Sox baseball team. Only it wasn't for a game, or a rock concert. It was to hear a message from Pastor Joel Osteen. Osteen heads Lakewood Church, in Houston, the largest church in America.
"For many years, people have heard that God's mad at them -- they can't live up to the standards. But our message is about the goodness of God, and it seems just that people come alive when they realize 'God is for me. He's got a plan for my life, and I can do something great. I can be who he wants me to be,'" Osteen said in an interview with "Good Morning America" anchor Robin Roberts.
It's a message that resonates with the millions who attend his services, watch him on TV and buy his books.
"I know that God speaks to him. I do know there is hope, and he will talk about hope, and that is what we need," said one attendee in Chicago.
"[H]e's talking about living your life to the fullest -- God has blessings for you. And I believe that," said another.
The day before the Chicago event, hundreds lined up for hours to get an advance copy of Osteen's latest book, "Every Day a Friday: How to Be Happier 7 Days a Week."
Click here to read an excerpt from Osteen's "Every Day a Friday."
The book's theme is simple: You can choose to be happy.
"I read some studies that said that people are happier on Friday. I thought, You know what? We should be happy every day. That's a choice that we can make," Osteen said.
It is simple but not easy.
"There's a lot pushing people down these days, from the economy to the wars. And you look up, and there are natural disasters, and I think you have to make up your mind in the midst of all this: I am going to find something to be grateful for," Osteen said.
Such simplicity and focusing on hope, happiness and prosperity have brought Osteen criticism for not emphasizing Scripture, sin and faith as its own reward.
In response, Osteen said: "I think it goes back to tradition, how we were raised. Jesus talked about everyday life, not just doctrine but how do we live? How do we forgive? How do we keep a good attitude when the economy is down?"
Lakewood Church was started by Osteen's father, John, in a lowly feed store in 1959. Today it occupies the former arena of the NBA's Houston Rockets, which the church renovated at a cost of more than $100 million. Tens of thousands fill the pews every week.
The church remains very much a family-run operation, starting with Osteen's wife, Victoria.
"Our first date was in this building, and we've been married close to 25 years. If God showed us all of that all at once, we probably would have run in the other direction. But it's just one day at a time, just trying to do your very best," she said.
And now the next generation of Osteens is beginning to get involved. Thirteen-year-old Alexandra sings at church events, and Jonathan, 16, is in the band.
"I would love for them [to follow in my footsteps]. I can't call them to do it. But I do think they feel something on the inside. There is a legacy, a responsibility that my dad started," Osteen said.
This legacy has grown into an empire.
"We take in about $80 million [per year]. It's not all from the church. Some of it's from the TV audience as well. It goes all over the world. If we take in 80, we spend 80. Victoria and I don't take a salary from the ministry. We've been blessed with our books and things," Osteen said.
Lakewood Church has a financial ministry, which Osteen admits is unusual.
"We believe in ministering to people in every area of their life. And you can't just get up there and tell them to have hope or think right. Some of them need to learn how to balance their checkbook or budget their money. We are just a big believer in 'Let's get practical,'" he said.
It's part of making the Church relevant to the modern world, he said.
"I think in some other countries that's why the church has dried up. They are having church like they had 50 years ago, and you know, the message doesn't change, but the times change. The music, the production, the lights: I believe if Jesus were here today he would have good production. He would have the best of things."
To Osteen the best of things -- prosperity -- is a form of God's blessing, one he wants for his followers. And that makes his critics pounce.
"I believe God, Jesus, died that we not just go to heaven but that we excel in this life. I never think you make money your goal. … God wants you to excel. Just keep him in first place and God will open up doors you never dreamed of," Osteen said.
Yet with all the doors that have opened for Osteen, he has not sought a broader platform. He said he does not want to be another Billy Graham, "America's Pastor."
"I don't mean that I don't want to become everything God wants me to be. But I think there was only one Billy Graham, and he's a friend, and I honor him. … I do feel like God's given us influence, and I want to use it any way we can," Osteen said.
Some would want or expect this to include culture and politics, meaning gay marriage and abortion. Osteen abstains.
"I just think I am good at not being sidetracked from what I am really called to do," he said. He doesn't want to distract his audience from his main message.
"To say, that guy is not for the war or for the war, and I differ on that. Or I differ on the political opinion over here. … I think it starts to narrow you. I mean, for a while … to be an evangelical meant you were a white Republican, and you were against this and against that. I don't want to be put into that mold, because then people judge you before they even listen. … I don't want to divide the very people I am trying to reach."