Joel Osteen: The Man Behind the Ministry

At 43, the gentle-mannered, unassuming Joel Osteen is one of television ministry's biggest celebrities, preaching to some 40,000 worshippers who congregate weekly in Houston to take in his message. And though he knows he's found his calling, even Osteen himself can't figure out how he got so big so fast.

A son of the Southern Baptist tradition, Osteen followed in the footsteps of his father, John Osteen, who opened Lakewood Church in a feed store in one of Houston's industrial zones back in 1959. As John Osteen's congregation grew, it moved from bigger building to bigger building -- helped enormously by a decision to move the ministry to television and out into the world.

Joel was a teenager at that point, had tried college for one year, and came home with the plan to move the ministry to television.

"My dad said, 'That sounds good,'" Osteen recalled. "So we purchased the equipment and a year later we were on air."

The decision changed Lakewood -- and the Osteen family -- forever.

"It changed it in that it started putting it on the map," Osteen told "Nightline" correspondent John Donvan. "And it was when we went on television that it really started growing."

For 17 years, John Osteen preached from the pulpit while Joel stood behind the scenes and turned it into television.

In 1999, the congregation of the Lakewood Church reached 6,000 members -- and John Osteen died. It was at that point, at the age of 35 without having ever preached a day in his life, that Joel Osteen decided to follow in the footsteps of his father.

"The first year I was nervous, and I talked real fast," Osteen said. "And you know I told a lot of stories. The first time I spoke I told a lot of stories about our family and just made people laugh."

As Osteen grew into his message -- a gentle, positive one that often sounds more like self-help than sermon -- so did the congregation, doubling that first year and then again and again.

The limelight became him, and his uplifting messages moved around the world and into a best-selling book, all without speaking of abortion, gay marriage, sacrifice or Satan.

Some of his critics attribute Osteen's popularity to his tendency to avoid confronting those issues head-on in favor of entertainment.

"I've heard him preach philosophy, psychology, positive thinking," said Lorenzo Walker of Mount Pilgrim Missionary Baptist Church. "I don't think much of his message. ... He doesn't get involved in controversies or sin."

And while some may disagree with Osteen's message, the numbers don't lie. And the simplicity of his sermons -- to go with the flow, to put aside negative thoughts, to visualize your best self -- seem to resonate in a meaningful way with the thousands upon thousands who connect with his quiet dynamism every Sunday.