Mysticism, according to its historical and psychological definitions, is the direct intuition or experience of God; and a mystic is a person who has, to a greater or less degree, such a direct experience -- one whose religion and life are centered, not merely on an accepted belief or practice, but on that which the person regards as first hand personal knowledge.
Evelyn UnderhillThe spiritual life of individuals has to be extended both vertically to God and horizontally to other souls; and the more it grows in both directions, the less merely individual and therefore more truly personal it will become.
Evelyn Underhill