Mysticism: A Study in Nature and Development of Spiritual Consciousness     by Evelyn Underhill
   Complete on-line book.
Abandonment to Divine Providence   by Jean-Pierre deCaussade
   "The life of faith is nothing but the continual pursuit of God through everything that disguises, disfigures, destroys, and, so to say, annihilates him....God ties your hands and feet to be able to carry on His work without interference; and you do nothing but struggle, and make every effort, but in vain, to break these sacred bonds, and to work yourself according to your own inclination. What infidelity! God requires no other work of you but to remain peacefully in your chains and weakness."
   Complete on-line book.
The Dark Night of the Soul    by St. John of the Cross
   "The Divine assails the soul in order to renew it and thus make it Divine; and, stripping it of the habitual affections and attachments of the old man, to which it is very closely united, knit together and conformed, destroys and consumes its spiritual substance, and absorbs it in deep and profound darkness. As a result of this, the soul feels itself to be perishing and melting away, in the presence and sight of its miseries, in a cruel spiritual death."
    Complete on-line book.
The Way of Christ     by Jacob Boehme
    "The soul groaned and cried to God, but it appeared to it that it had been completely cast out from before God's face, as if it could not gain one glance of grace, and stood in vain anguish as well as in great fear and dread.....Thus it fell into great sadness and misery, so that the joy and temporal pleasure of things pursued earlier became troublesome and boring."
    Complete on-line book
The Mystics of Islam     by Reynold A. Nicholson
    Complete on-line book.