Originally published in 2005 and selected for the Book Club in 2008, A New Earth, by Eckhart Tolle is “the most important book” she’s ever read (and it’s safe to say, she reads a lot).

She has selected Eckhart Tolle’s A New Earth: Awakening to Your Life’s Purpose for her book club, marking the first time she has chosen a publication twice. Winfrey, who launched her club in ...