In our last post we began looking at this crucial passage in Romans 8:13 which teaches us the importance of killing sin.
Romans 8:13For if you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body, you will live.”
Deeds of the body
The second question in our understanding of this passage comes in what Paul means by the “deeds of the body”. We may initially think that Paul only addresses those sins that we actually commit with our body parts such as our eyes, ears, and hands. But within the context of Paul’s argument throughout Romans 6-8, the deeds of the body can also be synonymous with the flesh. In other words, the deeds of the body can also be internal sins of the heart such as lust, greed, impatience, or an unforgiving spirit. They can also be external sins committed with our body such as sexual immorality, theft, or lying.
In the book of Colossians we find a complementary passage which commands us to put to death sin.
“Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry. On account of these the wrath of God is coming. In these you too once walked, when you were living in them. But now you must put them all away: anger, wrath, malice, slander, and obscene talk from your mouth” Colossians 3:5-8
From Paul’s list here we see that both internal and external sins must be put to death. Passion is an internal sin, while sexual immorality is an external sin. Evil desire is also an internal sin which could lead to covetousness and subsequent thievery. In the same manner, anger is an internal sin that can be expressed externally through slander or obscene talk. The list Paul uses here could be a summary of specific sins that he mentions in Romans 8:13 simply as “deeds of the body”.
We see many similarities between these two passages. In both cases, we are commanded to put to death sin. We are also warned of impending death if we live by the flesh. In Colossians Paul describes it as God’s coming wrath while in Romans he simply states it as death. Spiritual death under the excruciating wrath of God in hell becomes the final ramification for those who die in their sins and have not experienced the miracles of regeneration, justification, and union with Christ.
“M” is for Mortification
The third question we must understand is this: What does it look like to actually kill sin? How do we put do death these deeds of the body? The King James Version uses the word “mortify” which no longer really has much meaning in our contemporary culture. When people say that they are “mortified” it usually means that they are embarrassed beyond all measure and want to slink away in shame. The Puritans of old called this process of killing sin “mortification”. The word Paul uses here in Romans 8:13 to describe this act of killing sin is “thanatoo” which means to put to death and was often times used to describe an execution. Paul again uses the present active indicative verb choice to illustrate that this killing is not just a onetime action. Putting to death sin involves an ongoing, continual, brutal, endless lifestyle of mortification.
We have already seen how deceitful, tenacious, and corrupting indwelling sin truly is. Sin is a foe that will never back down. Sin does not take a half-time break in the locker room to catch its breath. Sin does not retreat to the beach for a day of relaxation and sunbathing. Sin does not fall asleep at the wheel because it has grown so tired after hours of dogging us. John Owen says this about sin: “Sin will not only be striving, acting, rebelling, troubling, disquieting, but if left alone, if not continually mortified, it will bring forth great, cursed, scandalous, soul-destroying sins.” Sin does not take a break, so neither should we when it comes to this battle. We can never sleep. What did Jesus remind His disciples just hours before His betrayal in Matthew 26:40-41: “And he came to the disciples and found them sleeping. And he said to Peter, “So, could you not watch with me one hour? Watch and pray that you may not enter into temptation. The spirit indeed is willing, but the flesh is weak.” Bishop Ryle says this, “Sin admits of no breathing time, no armistice, no truce.”
Randy Gardner holds the world record for going the longest time without any sleep—eleven days! In 1964, as a high school student in San Diego, California, he underwent a scientific study with a researcher from Stanford University to see how many days a person could go without sleep not using stimulants of any kind. Eventually the human body shuts down and has to give in to the innate need for sleep. We cannot physically stay awake forever. In stark contradiction to this, sin never sleeps. It stays awake incessantly.
Because sin never sleeps, continually pursues us, and desires nothing but a hostile takeover of our souls, we need to adopt the same attitude. We need to actively, consistently, and fervently kill sin. John Calvin comments on this passage in Romans 8:13 by saying that Paul “bids us to make every exertion to subdue sin’s lusts.” John Owen defines mortification this way: “To kill a man, or any other living thing, is to take away the principle of all his strength, vigour, and power, so that he cannot act or exert, or put forth any proper actings of his own.”
One caution needs to be articulated before we go any further. Ultimate mortification or total death of sin will never occur in this life. We will never totally kill all sin. This total victory over sin should never be an expected part of our progressive sanctification. Our aim should be to mortify or kill all sin, but in reality, this will never happen this side of heaven. We may experience seasons of wonderful success and victory against sin, but we will never get to the point where we no longer have to practice the grueling process of mortification. The moment we get to the point where we think that sin no longer can deceive us or manipulate us or that it somehow lies dormant within us, becomes that exact moment that we are the most vulnerable. The apostle John clearly tells us in 1 John 1:8 that “If we say we have no sin, we deceive ourselves, and the truth is not in us.”
 John Owen, The Mortification of Sin, (Ross-shire, Scotland: Christian Heritage, 2002) 32
 J.C. Ryle, Holiness, (England: Evangelical Press, reprinted 2001) 54
 John Calvin, Calvin’s Commentaries Volume XIX Acts-Romans, (Grand Rapids, Michigan: Baker Books, 2005) , 294.
 Sinclair Ferguson, John Owen on the Christian Life, (Carlisle, Pennsylvania: Banner of Truth Trust, 1987), 146