This book presents a compilation of the greatest works on spiritual development and life by St. Theresa of Avilla. As a reformer of the church doctrines, Theresa rethought the notion of spiritual development and created her own methodic of contemplative life that should lead to spiritual perfection. As a creator of the new order, she created these works to teach her followers of her methods, which consisted of meditation, spiritual quiet, the daily prayer, which should eventually lead to spiritual unity with the Creator. Each of the presented books had a significant impact on the development of Christian thought and belonged to the most important achievements of the Spanish literary heritage. This edition includes: "The Interior Castle" - is a guide to spiritual development through service and prayer. It is one of the leading books in the oeuvre of Saint Therese of Avilla and one of the most famous works in Spanish literature. The book was inspired by Theresa's vision of a soul as a diamond in the shape of a castle with seven mansions. She interpreted this dream as the spiritual journey through seven stages, after which a soul is united with God. "Way of Perfection" - is a spiritual instruction given by Theresa of Avila to the nuns of her new Order. She believed that spiritual perfection could be attained by overcoming four stages of prayer: meditation, quiet, repose of soul, and perfect union with God. According to Theresa, the last stage of spiritual development can often be equated to rapture. "The Life of St. Theresa of Avila" - In this book, she gives a warm and accessible account of her life, from childhood to the conflicts and crises she had, to her decision to enter a prayer life and become a spiritual leader and a passionate reformer of the church doctrines. Here, she talks about her education in sixteenth-century Spain, physical afflictions, and spiritual crises which led to visions and mystical encounters. She also gives lyrical descriptions of the ecstatic feelings she experienced during her raptures. Alongside Don Quixote, this book is a treasure of Spanish prose and one of the most outstanding achievements of the world's literature.