(Romans 8:13)
“For if ye live after the flesh, ye shall die: but if ye through the Spirit do mortify the deeds of the body, ye shall live.”

Death is an unpleasant subject. Especially when it is the death of someone or something we love. We are in a life and death battle against sin. Just as David on the battle field with Goliath said, “The battle’s is not mine but the Lords” so we too can only prevail by the power of God. To live after the flesh is to submit to the power of enemy, and to allow ourselves to be in complete subjection to the old nature. The doctrine of mortification is the flip side of the coin. Our salvation does not destroy the the old nature of sin and the desires of the flesh, but the indwelling of the Holy Spirit does give us power to subdue it. To bring it into subjection. The natural desires of the flesh must become our servant and not master! You cannot kill the old nature, but you can mortify (kill) the deeds that it once produced in your life. You are either killing sin or sin is killing you!

(Romans 13:14)