The Power of Now is a spiritual guidebook by Eckhart Tolle that explores the concept of living in the present moment. Tolle emphasizes the importance of mindfulness and the liberation that comes from letting go of past regrets and future anxieties. Through practical advice and insightful teachings, he encourages readers to embrace the power of now and find inner peace and fulfillment. The Power of Now has become a popular book for those seeking personal growth and spiritual enlightenment.