Spiritual formation is the process of strengthening the inner core of a person—their spiritual life. Spiritual formation involves learning about self (self-awareness) and learning about God. It involves growth, creative tension, experiences of disequilibrium, and it leads to change.
Many traditions name spiritual disciplines including prayer, meditation, solitude, and fasting, and most focus upon seeking knowledge of the Divine in some way. Many coaching philosophies speak respectfully of prayer and meditation and include them among healthy life practices that reduce stress, increase mindfulness, cultivate gratitude, and help people to practice differentiation in the midst of conflict and high anxiety.
Christian spiritual formation stands apart because it is specifically focused on the unveiled story of the God-man who rescues people from their inner, and relational, brokenness, and proceeds to the end of remaking the renegade world. Christian spiritual formation is also uniquely a response to something God has done first. It is centered on God's active pursuit of people, not peoples' pursuit of him. It reflects and meditates upon—marvels at—him as he is restoring them to a right relationship with himself and beginning the renewal of the entire universe.
In our highly individualistic culture in the West, especially in America, it is possible to think of spiritual formation as an individual pursuit. It is about "me and God"—possibly in that order.
Spiritual formation is a relational process.
What we've learned, and what is contrary to our instincts in our culture is that spiritual formation is a relational process. It takes others to help us see ourselves as we are, without blinders on: people who will pursue us and speak loving truth to us even putting our friendship at risk to do so. It also takes the richness of others' experience with God while wrestling with issues like mine to help me see things about him that I can't see on my own. Also....
Spiritual formation is not a program.
I am not saying that organization, boundaries, and intention are not needed, helpful tools in our spiritual formation. But it is to say that spiritual formation can't be reduced to a program. It can't be accomplished in the confines of a semester course, or even a two year program. Or a seminary education. Intensive content and learning are powerful aspects of spiritual formation. But often living life together with others in the ordinary is a more authentic arena. Experiencing the mundane, the day to day routines of marriage or work, or friendship, of pushing back weeds from gardens, of illness, loss of loved ones, and tasting drudgery—these are the wider, truer context in which spiritual formation takes place.
If spiritual formation is not a program, it's not one size fits all.
Eugene Peterson says the process is "taking careful note of what God is doing in one another's lives and applying scripture and the Spirit's wisdom to one another."
That's uncomfortably non-programmatic.