Getting a firm understanding of “it’s no longer I who lives, but Christ living in me” is the foundation to living by Faith in the flesh. Your flesh is the “vessel” in which you operate out of. Faith is the source of your operation.
Galatians 2: 20 NASB20
I have been crucified with Christ, and it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh I live by faith in the Son of God, who loved me and gave Himself up for me.