This book is the first volume of the Emerald Hills of the Heart series, which brings out a comprehensive and unique examination of concepts and terms associated with sufism in Islam. In this volume, Gulen looks at fifty different concepts. With an introduction on the heart and some of its dynamics, this work is a rich addition with more gates into spirituality. Concepts examined include freedom, altruism, wisdom, sainthood, intoxication and sobriety, wakefullness and the universal man. This book is a comprehensive study of concepts and terms associated with Sufi traditions of Islam. Gulen's informative analysis of Sufi ideas is a must read for those who seek a understanding of the dynamics of sufism. For Gulen, sufism is a form of self-purification leading to inner dimension of Islamic rituals, a deeper understanding of the divine acts, and a greater knowledge and love of the Divine. The continual process of spiritual development in sufism along a path of the innate human poverty, helplessnes, and powerlessnes before God is undertaken in the knowledge that everything come from God. The first volume of the Emerald Hills of the Heart presents such sufi concepts like repentance, reflection, self-criticism, asceticism, piety, abstinence, self-supervision and sincerity.