The list author says: "Spiritual reading is a practice of reading books and articles about spirituality with the purpose of growing in holiness.
Spiritual reading is devoted to the reading of lives of saints, writings of Doctors and the Fathers of the Church, theological works written by holy people, and doctrinal writings of Church authorities. It is different from lectio divina which focuses on the bible.
The biblical basis is St. Paul's advice "Attend to reading" (1 Tim 4:13) which meant that Timothy his disciple should "apply to the reading of holy books, not in a passing way and for a short time, but regularly and for a considerable time," said St. Alphonsus Liguori, Doctor of the Catholic Church on Moral theology. St. Bernard of Clairvaux said that "spiritual reading and prayer are the arms by which hell is conquered and paradise won."
All the founders of religious orders have strongly recommended this holy exercise, states St. Alphonsus. And in the early 20th century, Pope St. Pius X recommended this practice as a means of holiness."