Drawing from sacred scriptures, world religions, literature, philosophy and psychology, this monograph explores them as universal sources of religious experience and mysticism. It systematically establishes the similarities and differences between them as well as their distinctions from aesthetic experiences and mystical thought. Examples from religious experience show that it is perceived in space-time categories while mystical experience transcends all these experiencing union. It is this characteristic of mysticism which unifies World Mysticism regardless of the religious, cultural, or philosophical background. This book is divided into three major parts: Part I focuses on 'Religious Experience'; Part II on Mysticism; and Part III integrates the results within the larger scope of the awareness of the diversity of Transcendence. The introduction and conclusion structure both the inquiry and results.