Just as physical walking is good for us, also spiritual exercise, following Christ actively, is good for us. The Lord through the pen of Paul commands us to walk in Christ – meaning we are to be rooted in Christ, and built up in Christ, and established, and thankful, walking, taking steps, actively living life. Paul then warns us against wandering away from Christ, lured away by contrary philosophy, deceit, human tradition or spirits. Christ is where the whole fullness of deity dwells bodily. Verses 9-15 mention Christ as being “with him” or “in him” 7 times. Circumcision, a “cutting off” of the foreskin signifies our being separated from the world, and it signifies the work of Christ, who was cut off from the world in his death at the Cross. Our hearts are circumcised, separated from the world, set apart to God in Christ. We have died to sin and been raised to life in Christ, forgiven. The power of God who raised Jesus from the dead is the same power that enables us to walk, to live, for Christ. We should walk daily exercising faith to be spiritually fit.