Spiritual formation is foundational for mission and ministry. It involves the process of the individual or the community being shaped into the image and likeness of Christ. Paul, as a missionary church planter did not claim to have completed his task until the whole body of believers reached the entire measure of the fullness of Christ. It also is vitally important for all aspects of human development because people who are not being formed in the image of Christ are less than God intended them to be. In a real sense, you reach your full humanity as you become more Christlike for Christ is the full, complete human being.
Dietrich Bonhoeffer, a Lutheran Pastor, wrote in his book, Ethics, on the question of spiritual formation in the life of a Christian:
"The form of Jesus Christ takes form in man. Man does not take on an independent form of his own, but what gives him form and what maintains him in his new form is always solely the form of Jesus Christ Himself. It is therefore not a vain imitation or repetition of Christ's form but Christ's form itself which takes form in man. And again, man is not transformed into a form which is alien to him, the form of God, but into his own form, the form which is essentially proper to him. Man becomes man because God became man. But man does not become God. It is not he, therefore, who was or is able to accomplish his own transformation, but it is God who changes his form into the form of man, so that man may become, not indeed God, but, in the eyes of God, man."
However, spiritual formation is far more than behaviour change. You can memorise Bible verses, attend church five times a week, pray an hour per day, fast weekly, and still make no progress in spiritual formation. In saying that I am not saying behaviour is not important, but only as it is a sincere indication of inner heart development. Likewise, spiritual formation is not merely about the understanding of biblical or theological knowledge. A person may have a PhD in Theology and not necessarily have made any progress in spiritual formation. Instead, spiritual formation is a process that takes place within a person, and this is not something that can be easily measured, regulated, or predicted. Spiritual formation is a lifelong process and is not a task that can be completed in a short period of time.
Spiritual formation is the process of transformation. It encompasses the traditional understandings of emotional maturity, character development and personal achievement, but goes beyond that to address the discovery of identity and destiny. 'Who am I?' and 'Why am I here?' are the fundamental questions for which human beings are programmed to seek answers. Spiritual formation is the process of the discovery of the answers to these questions.