Twenty years ago, Marianne Williamson's groundbreaking book, A Return to Love, became a global phenomenon that helped open the heart space of millions Published in 23 languages, it spent 39 weeks on The New York Times bestseller list. The book so moved Oprah that she bought 1,000 copies, gave them to her audience and invited Marianne on The Oprah Winfrey Show.

Now, 20 years later, Marianne returns to Chicago to discuss her landmark work. Watch the clips below to find out just how powerfully the life lessons from A Return to Love still resonate today.

Oprah shares her favorite passage from A Return to Love:

Why Marianne says we're both better—and worse—off than we were 20 years ago:

How to recognize the miracles that already exist in your life:

Why Marianne says we should all pray for those who've wronged us: