I began teaching spiritual formation and transformation in 1977, to pastors and Christian leaders. Since then I have taught my materials in a Chinese context (Singapore, New York City, and Vancouver), an African and African-American context (Payne Theological Seminary; Kenya; black conferences; Palmer Theological Seminary; AME pastors in Trinidad); in India; in a multiracial context in Brazil; in various pastors and leaders conferences around the U.S; at Northern Baptist Theological Seminary (M.Div. and D.Min. programs); and, of course, in my home church in Monroe, Michigan.
Necessary to living a transformational life in Christ is ongoing self-examination. 2 Corinthians 13:5 says, Examine yourselves, to see whether you are in the faith. Test yourselves. Or do you not realize this about yourselves, that Jesus Christ is in you?—unless indeed you fail to meet the test!
This is "Search me O God and know my heart" time.
One of my favorite self-examination verses is Proverbs 20:5 - The purposes of a person’s heart are deep waters, but one who has insight draws them out. Behavioral transformation begins with heart transformation. Famously, being comes before doing.
In my case, to walk better, a full transformation of my right hip was needed. As I write this I am recovering from total hip replacement surgery. Both before, and after, surgery, my surgeon took x-rays and MRIs to look deep into my hip joint. In various ways, he examined me. His method was not superficial. In a similar way I have learned that, in order to change my spiritual heart, God looks deep inside me.
I see this not only in the Scriptures, but in the historical literature of spiritual transformation. Since 1977 I have engaged in learning from the likes of St Teresa of Avila, St John of the Cross, Thomas Kelly, Howard Thurman, Thomas Merton, the Desert Fathers, Henri Nouwen, Dallas Willard, Ruth Haley Barton, and Richard Foster. They all teach, from experience, about the "inner life."
When I spend extended times praying, much of those times are being searched-out by the Holy Spirit. My 3500+ pages of journal entries are heavily populated with inner transformation. My journal is 95% about what God is saying to and doin in me. Anyone who enters into the great journey of the renovation of the heart experiences this.
Self-examination is not to bring self-hatred. I think of it as another rescue. God has saved me from myself. And, there is no condemnation for those who are in Christ Jesus.
If everyone engaged in critical self-evaluation, before God in his presence, the world would be better. There would be more compassion. Note: more compassion, not more agreement.
One result of decades of allowing the Spirit to examine me is that, while making judgments is needed, judgmentalism has receded. C.S. Lewis wrote that the true Christian's nostrils must be constantly attuned to the inner cesspool. I know what Lewis means by this.
For me, over decades, this is ongoing, and freeing. If you want to make a beginning, I recommend this book, which I used for two years back in the 1980s: A Guide to Prayer for Ministers and Other Servants, by Norman Sawchuck and Reuben Job.