'The Mastery of Love' by Don Miguel Ruiz is a spiritual guide to cultivating love and harmony in relationships. Drawing on ancient Toltec wisdom, this book explores the importance of self-love, forgiveness, and authenticity in creating fulfilling relationships. By letting go of fear and embracing love, individuals can transform their relationships and experience true happiness. 'The Mastery of Love' offers practical advice and powerful insights to help readers navigate the complexities of relationships and create a more loving and compassionate world.