Video from Conversatio Divina
“Spiritual formation” is the process through which those who love and trust Jesus Christ effectively take on His character. When this process is what it should be, they increasingly live their lives as He would if He were in their place. Their outward conformity to His example and His instructions rises toward fullness as their inward sources of action take on the same character as His. They come more and more to share His vision, love, hope, feelings and habits. In the language of His “Great Commission” to His disciples, they are “taught to obey everything I have commanded you.” (Matt. 28:20)
This process of “conformation to Christ,” as we might more appropriately call it, is constantly supported by grace, and otherwise would be impossible. But it is not therefore passive. Grace is opposed to earning, not to effort. In fact, nothing inspires and enhances effort like the experience of Grace.
Yet it is today necessary to assert boldly and often that becoming Christlike never occurs without intense and well-informed action on our part. This in turn cannot be reliably sustained outside of a like-minded fellowship. Our churches will be centers of spiritual formation only as they understand what really does make for Christlikeness and communicate it to individuals, through teaching and example, in a convincing and supportive fashion..." from the article: The Spirit is Willing