Pastor Rick Warren, author of "The Purpose Driven Life: What on Earth Am I Here For?," joins "Starting Point" on Thursday to discuss his updated bestseller and how the culture of religion in the United States has changed in the past ten years.

"The audience has changed," Pastor Warren explains. "A girl who was 12 years old when the book came out is now 22. She needs to know her purpose. I really refocused the book for people in their 20s and 30s who may have ignored it 10 years ago."

He also adds that new technology encouraged him to update his bestseller, which now offers 30-minute audio teachings in each chapter.

In addition to his updated book, Pastor Warren discusses how Christianity has changed in the United States since his bestseller was first published. "Cultural Christianity is dying," he says. "True Christianity is not." He adds that while fewer people today may identify with the term "Protestant," it does not mean that the Church is dying.