|Spiritual formation is theological and psychological|
The processes of spiritual formation thus understood require precise, testable, thorough knowledge of the human self. Psychological and theological understanding of the spiritual life must go hand in hand. Neither of them is complete without the other.
A psychology that is Christian, in the sense of a comprehensive understanding of the facts of spiritual life and growth, should be a top priority for disciples of Jesus, particularly those who work in the various fields of psychology and who consider it an intellectual and practical discipline. No understanding of the human self can be theoretically or practically adequate if it does not deal with the spiritual life.
From The Great Omission: Reclaiming Jesus’s Essential Teachings on Discipleship. Copyright © 2006 by Dallas Willard. All rights reserved. Used with permission of HarperCollins Publishers.