Mysticism is the belief that spiritual reality is perceived apart from the human intellect and natural senses. It looks for truth internally, weighing feelings, intuition, and other internal sensations more heavily than objective, observable, external data. Mysticism ultimately derives its authority from a self-actualized, self-authenticated light rising from within. Its source of truth is spontaneous feeling rather than objective fact. The most extreme and complex forms of mysticism are found in Hinduism and its western reflection, New Age philosophy.
John MacArthur