The book attempts to unravel the nature of mysticism in the life and teachings of Shirdi Sai in the context of various types of mysticism seen or experienced in religions and Spiritual Masters since the Vedic times. The logic and relevance of Mysticism through ages have been analysed starting from the Vedic rites to the messages of the Upanishads, Srimad Bhagavad Gita, Yoga Sutras, Buddhism, Christianity, Islam-Sufism, Sikkhism, Bhakti movements and other religions or spiritual paths.This book can serve as a useful document for devotees, researches and students of comparative religions, metaphysics and spiritualism.