Celebration of Discipline: The Path to Spiritual Growth, Richard J. Foster - The classic study on the spiritual disciplines.

               The Character of God: Discovering the..., R. C. Sproul

               Conformed to His Image: Biblical and Practical Approaches to Spiritual Formation, Kenneth Boa - This is a great and fairly comprehensive introduction to the subject of spiritual formation.  If you want a great overview on the subject start with this book.  This also is written as a textbook for seminaries or Bible Colleges.

               Desiring God: Meditations of a Christian..., John Piper

 God is No Fool, Lois A. Cheney

               The God Who Hears, W. Bingham Hunter

               Holiness: Its Nature, Hindrances,..., J. C. Ryle

             The Holiness of God, R. C. Sproul - A profound look at the character of God, especially His holiness and how God's holiness affects every aspect of our lives.  R C Sproul is one of my favorite theologians.  This book is profound and very insightful, yet easy to read, understand and apply.  A classic and one of my favorites.

                Invitation to a Journey: A Road Map for Spiritual Formation, M. Robert Mulholland - A good basic overview of spiritual formation.

                Keep in Step With the Spirit, J. I. Packer - Packer focuses on the work and ministry of the Holy Spirit in this book.  It is a strong encouragement to a deeper Christian experience and to acquire a spirit-filled character.

                Knowing God, J. I. Packer

                The Knowledge of the Holy: The Attributes of God, A. W. Tozer - A classic!  A study on the attributes of God.

                Method for Prayer, Matthew Henry

                The Mortification of Sin, John Owen - A classic study on mortification by one of the most highly regarded Puritan theologians.  This study provides great biblical principles to help believers live lives of holiness.

                The Pilgrim's Progress in Modern English, John Bunyan

                The Pleasures of God: Meditations on..., John Piper

                Pursuit of God, A. W. Tozer - Another spiritual formation classic by A. W. Tozer.

                The Pursuit of Holiness, Jerry Bridges - One of the best practical books available on what it means to live a holy life.

                Revival: A People Saturated with God, Brian H. Edwards - This study on revival from Scripture and from history is designed to inform the mind and inflame the heart.  This book gives a greater understanding of revival and creates a longing for God.  I was greatly motivated by reading this book to long for revival and to pray that God would be glorified and bring personal and corporate revival.

                Religious Affections, Jonathan Edwards - Edwards is an intellectual giant and one of the greatest theologians who ever lived on the American continent.   This is Edwards classic work distinguishing between true and false religion, by showing what are the genuine signs of a saving work of the Holy Spirit.  In doing this He encourages the development of the spiritual life of the reader.  It is not easy to read but it does challenge your thinking and move you to delight in God.

                Renovation of the Heart: Putting on the Character of Christ, Dallas Willard - How can I be changed into the likeness of Jesus Christ?  This book insightfully sets out to answer this question.  His approach is not simplistic but it is deep, clear and practical instruction on what it means to live as a disciple of Jesus Christ.

                Satisfy Your Soul: Restoring the Heart of Christian Spirituality, Bruce Demarest - A wise study of the life-long process of inner transformation.  Balanced, biblical and practical.

                The Screwtape Letters, C. S. Lewis

 Seeing God: Jonathan Edwards and Spiritual Discernment, Gerald R. McDermott - McDermott makes Jonathan Edwards' insights in his book Religious Affections practical and understandable for today.  He clarifies the signs of genuine Christianity so that we can have insight into true and false spirituality.  If you have trouble getting a handle on what Edwards is saying this will help a lot.  You will also gain insight that will help your spiritual life; your appreciation, delight and enjoyment of God should grow and develop.