The Way of Perfection by Saint Teresa of Avila (A Christian classic!)
The Dialogue of Saint Catherine of Siena
Dark Night of the Soul (Annotated)
Interior Castle (Dover Thrift Editions)
Spiritual Exercises of St. Ignatius of Loyola
The Interior Castle
On Loving God
Ascent of Mount Carmel
Uniformity with God's Will & The Practice of the Love of Jesus Christ
The Complete Works of Saint John of the Cross, Volume 1 of 2