Romans 8:13 (HCSB)

…for if you live according to the flesh, you are going to die. But if by the Spirit you put to death the deeds of the body, you will live. (Romans 8:13 HCSB)

The Puritan John Owen, in his book, The Mortification of Sin, published in 1656, argues from Romans 8:13 that Christians must strive to mortify sin because sin remains in them despite the fact that they are new creatures in Christ. Owen stresses that to mortify sin is to put it to death. He offers six reasons why Christians must continuously strive to kill the sin in their lives.

1. Indwelling sin always remains in us while we are in this world. Although some people believe we are able to keep God’s commands perfectly and wholly in this life, the Bible does not support this view (Philippians 3:12; 1 John 1:8). As long as we live in this world sin will be part of who we are. Granted, we can make progress every day toward the elimination of sin from our lives, but we will not be sin free until we get to heaven.
2. Sin is always trying to lead us astray. Owen says, “When sin lets us alone, we may let sin alone; but sin is always active... We should therefore fight against it and be vigorous at all times and in all conditions, even when there is the least suspicion.” He adds, “If sin is always acting, we are in trouble if we are not always mortifying… There is no safety but in a constant warfare for those who desire deliverance form sin’s perplexing rebellion.”
3. If we don’t mortify sin it will produce terrible results in us (Galatians 5:19-20).David was guilty of adultery, murder, etc. because he failed to mortify his sin. “Mortification withers the root and strikes at the head of sin every hour. The best saints in the world are in danger of a fall if found negligent in this important duty!”
4. God gave us the Holy Spirit and our new nature to oppose sin and lust (Galatians 5:17; 2 Peter 1:4). These are the necessary weapons, along with Scripture (Ephesians 6:17), for killing the sins that continuously hound us.
5. If we don’t mortify the flesh we will decay inside and not experience renewal. “Indeed, my life is consumed with grief and my years with groaning; my strength has failed because of my sinfulness, and my bones waste away” (Psalm 31:10 HCSB; cf. Psalm 38:3-5; 40:12). What a sad thing for people who once walked close to God fall away from him because they fail to put sin to death. It’s simple: either we kill sin or it will kill us.
6. Our spiritual growth is our daily duty. Paul makes this duty plain: “Therefore, dear friends, since we have such promises, let us cleanse ourselves from every impurity of the flesh and spirit, completing our sanctification in the fear of God.” (2 Corinthians 7:1 HCSB) Owen writes: “We will not be making progress in holiness without walking over the bellies of our lusts. He who does not kill sin along the way is making no progress in his journey.”

Prayer: Father, thank you for using John Owen to lead me to see that mortification has great practical benefit to me and that failure to mortify my flesh does terrible damage to my walk with you and my witness to others.