ANSWER: The word signifies mysterious, hidden, incomprehensible. To a worldly person a spiritual experience of the witness of the Holy Spirit and of Communion with God is mystical. Most ardent piety breathes in the hymns and other writings of this good lady persecuted and imprisoned by a church so fallen that it could not appreciate the seraphic ardor of this woman. All true Christians are mystics. Only nominal Christians and worldlings dislike the term and try to cast reproach upon it.
— Steele's Answers pp. 196.