It is difficult for me to chose one, because part of my appreciation for their advice is dependent on my present needs.
Catherine of Siena’s The Dialogues is great for people who are feeling overwhelemd by life in general. It has so much advice for every aspect of life, but the overwhelming message is God’s love for us and our obligations to love others.
In the area of spiritual development, Teresa of Avila’s writings are my favorite to read. Her biography inspired me, because I found it strange on some one who became so reknowned for her mystical experiences and spiritual wisdom, was not always sure that being a nun was the right vocation for her. Many saints’ seemed to have always known that they were called to serve God in a specific way, and as I am not sure what he wants from me, those types of life stories are not very helpful for me right now.
I found the fact that she experienced spiritual sryness incredibly encouraging. I also like her guide lines about mental prayer being a conversation with God, and how to increase a capacity for mental prayer by reading inspriational books and vocal prayer. I have read her autobiography and am working on The Way of Perfection.
I also loved Alphonsus Liguori’s The Practice of the Love of Jesus Christ, which is divided into chapters based on the passage in 1 Corinithians 13:4-7 (about love is patient…love is kind). It is a great meditation that expresses ways in which Jesus’ love for us exemplified these s attributes, and how we can express our love for him in return. He pulls form writings of many saints, in addition to providing his own insights, and ends each chapter with a wonderful prayer. It amuses me how he refers to Teresa of Avila as “Mother Teresa.” I kept it under my pillow and read a chapter each night before I went to sleep.
Francis de Sales Introduction to the Devout Life is a great handbook about most of the curves that life is apt to throw at you, and how to persevere, and how to recover when you fall. I profited much for his guidliens on mental prayer.
All of these authors write in an accessible style, which makes me feel as if I am having a personal conversation or lesson from them. I think Francis de Sales is probably the dryest, of the lot, but right now I cherish writing from the saints, more than biographies about them. I feel that reading their writings gives me better access to the type of advice that made them esteeemed, than reading about their lives with a few quotes from them, and I feel that I need all he advice I can get. Besides, each of these books have a little about the person as a preface.