Spiritual formation is: the ongoing process of Christ forming himself in our heart (spirit); the ever-increasing heart-morphing into Christlikeness.
Galatians 4:19 is a key verse here. It reads: My dear children, for whom I am again in the pains of childbirth until Christ is formed in you,...
I like how Renovare's Life With God Bible expresses the meaning of this verse and the nature of spiritual formation.
"A hallmark verse for spiritual formation, Gal. 4:19 provides an image of the process of growth for Christians. In this picture it is Christ who is growing in us, rather than we who are growing in Christ. Christ is formed in us by the power of the Holy Spirit as we respond to his ever-present grace in our lives. This occurs in daily, ordinary life as we "practice the presence of God" in our work, our play, our relationships, and all of life. By the Spirit in our hearts we cry out to God "Abba! Father!" (Gal. 4:6) many times throughout the course of a day, acknowledging who we are and whose we are. Christ is also formed in us as we present ourselves as living sacrifices to him through the Spiritual Disciplines, which, far from being the binding legalism Paul condemns in this letter, are the loving response of disciples to God's grace.
Steadily, gradually, Christ looms larger and larger within us. We find ourselves thinking, feeling, believing, serving, and living ore like him. Not only are we becoming more like Jesus; we are becoming more human, more ourselves.
The work of spiritual formation is the subject of this letter [Galatians]. That the Galatians were submitting again to a yoke of slavery - the opposite of spiritual formation - prompted Paul to couch his commuication in the vocabulary of freedom. Spiritual formation and freedom have a dynamic relationship. Curtail one, and the other is stifled. Grow in one, and the other flourishes. Five dimensions of spiritual formation emerge from the text as a result of Paul's emphasis on freedom. These are seismic shifts in the core of his being as Christ is formed in him, in the Galatians, andin us."
- The Life with God Bible NRSV, Renovare (Author), Richard J. Foster (Author), Dallas Willard (Author), Walter Brueggemann (Author), Eugene H. Peterson (Author), Bruce Demarest (Author), Evan Howard (Author), James Earl Massey (Author), Catherine Taylor (Author), Rebecca Gaudino (Illustrator)
Recommendations for this study Bible include:
“The Renovaré Spiritual Formation Bible … is unrivaled as a classic work of biblical theology suffused with a pastoral heart.” (Brennan Manning, author of Ruthless Trust )
“…[T]he most spiritually-impactful Bible of our time.” (John Ortberg, Teaching Pastor, Menlo Park Presbyterian Church, author of If You Want to Walk on Water, You’ve Got to Get Out of the Boat )
“This Bible is greatly needed.” (Tony Campolo, author of It's Friday but Sunday's Coming )
“With great enthusiasm, I open The Renovaré Spiritual Formation Bible. One could not assemble a finer team to compile it.” (Max Lucado, author of Come Thirsty and Traveling Light )
“This Bible helps us desire intimacy with God, not just know the typical facts and knowledge. (Dan Kimball, author of The Emerging Church, and Pastor of Vintage Faith Church )
“[An] outstanding resource...Christians of many different traditions will appreciate this ecumenical resource devoted to spiritual renewal.” (Publishers Weekly )
“...Many original and stimulating insights for the spiritual lives of contemporary Christians.” (Christian Century )
“This study Bible is both serious and accessible.” (Tulsa World )