9 Ways to Mortify Sin

Romans 8:13 says we must put to death the deeds of our flesh. In short, we must mortify sin.

John Owen wrote THE book on mortifying sin. His several-hundred-page magnum opus on mortifying sin is an exposition of Romans 8:13. The most well-known statement from this work is this: “Be killing sin or it will be killing you.” And probably my favorite part of the book, and where He gets super practical is when he answers the question, “What does this book like? How do you mortify sin?”

Here are 9 of the directives that Owen gives.

1. Diagnose sin’s severity. The longer you allow sin to go on, the harder it is to kill. The longer you indulge in sin, the stronger it gets. The more excuses and justifying of sin, the more severe it can become. We must know what we are up against if we hope to defeat it. If it is habitual, you must be more calculated and more focused.

EXAMPLE – If you’ve been looking at pornography for 20 years, you cannot overcome porn by simply wanting to change. You must plan to radically change and do whatever it takes, because it is severe.    

1. Grasp sin’s serious consequences. Evaluate the outcome of what might happen if you don’t stop sinning. Other than having a reasonable case against your own salvation, what would your life look like if you never changed – if you never repented? Common consequences include hardening of the heart, God’s chastening, and lack of joy.

EXAMPLE – If you are considering committing adultery, you need to consider the plethora of consequences that can follow and be sure your sin will find you out! (Num 32:23)

1. Be convinced of your guilt. Know what the Bible says about your sin. A purpose of God’s law is to bring guilt. And if you don’t feel shame for your sin, it could be because you haven’t yet looked at what the Bible has to say about it.

Owen wrote, “Bring the holy law of God into thy conscience, lay thy corruption to it, pray that thou mayst be affected with it.”

Meditate on as many Scriptures as you can find and then try to make room for that very sin. Ask yourself if you can thumb your nose at the cross where Jesus suffered, bled and died for that very sin you are holding onto.

EXAMPLE – If you are quick to anger and are annoyed by things not going the way you want, spend a good amount of time studying the long-suffering patient nature of God towards the Hebrews in the wilderness or Jesus with His disciples.

1. Earnestly desire deliverance. How desperate do you to pray to God for help? For assistance? For strength to avoid the temptation?

Again, Owen reminds us that “longing, breathing, and panting after deliverance is a grace in itself, that hath a mighty power to conform the soul into the likeness of the thing longed after. Unless thou longest for deliverance thou shalt not have it.”

If you want to be rid of sin, show God. Prove it. Cry out often. Beg him. Don’t be satisfied with anything else.

EXAMPLE – If you are tired of a spirit of apathy or idleness, how frequently do you talk to God about it? Are you wearing God out with your petitions for fervor? For zeal? Is it a frequent prayer request for you in your small group? Bible study?

1. Consider the relationship between your sins and your natural temperament. The key here is knowing yourself.  

EXAMPLE – If you are prone to worldly living and indulging in material pleasures, don’t surf the internet. Don’t go shopping often. Don’t visit Amazon. Do spend time with worldly people. If your temperament is to have things, have less things. And pray for contentment.  

1. Avoid occasions that incite sin. Romans 13:14 comes to mind where Paul says we must not starve the flesh or not give any provision for the flesh. Make that temptation weaker. If you get close to sin, you are playing with fire. If you want to avoid sin, stay away from that slippery slope.

EXAMPLE – If you struggle with drunkenness, don’t go to bars. Don’t eat out during happy hour. Don’t hang out with people who drink alcohol.

1. Address sin’s first signs. Owen says that it is hard to stop sin if we allow it to grow. Sin begets sin, just like water turns into a flood. Owen says we must look for the “first actings” of sin. Learn to diagnose the sin.

Work methodically and slowly through James 1:14-15 – “But each person is tempted when he is lured and enticed by his own desire. Then desire when it has conceived gives birth to sin, and sin when it is fully grown brings forth death.” Find a person who has experienced victory over the very sin you need to mortify and ask them for tell-tale signs of their sin.

EXAMPLE – If you struggle with the sin of coveting or envy, some of the 1^st signs of giving into that temptation would be a lack of cultivating thankfulness and gratitude of what God is doing or a lack of acknowledging the faithful provisions of God.

1. Mediate on God’s glory. This is the “put on” of mortification. Instead of feeding sin, glorify God. If you see God’s glory, you will be aware of your sin and the need for God’s glory.

Isaiah (Isa 6:1-7) needed cleansing; he needed mortification. He knew he needed this because He saw God’s glory. This point of mortification is screaming at our need to study deep into the righteous character of God. Sin does not grow well in a hear that is captivated by the glory of God.

EXAMPLE – If you give into temptation for deceit or lying, mediate deep and wide on the truthfulness of God. Think long and heard about how you can rely on every promise made in the Bible and why that is eternally important for us and how we cannot live outside of that hope. And then remind yourself people rely on you as well that you are telling the truth.

1. Don’t rush to comfort yourself. What an interesting admonition as a means of mortification. This is a needed caution. He is saying, “Don’t get overconfident.” One victory is not every victory. Sin is so deceitful. Just when we think we have defeated sin, it will find a way.  

The good news is that whole sin is deceptive and strong, the Holy Spirit indwelling us is stronger and reliable – “Let us then with confidence draw near to the throne of grace, that we may receive mercy and find grace to help in time of need” (Heb 4:16).

Owen writes, “Mortification of any sin must be by a supply of grace. Of our selves we cannot do it.”

We must have the Holy Spirit, and the good news is…Christian…we do!