How to Kill Sin: John Owen’s The Mortification of Sin

Paul Rutherford provides an overview of the Puritan John Owen’s classic book The Mortification of Sin.

Introduction

In my early twenties I confessed to a friend an ongoing battle with sin. He suggested I read John Owen’s book, The Mortification of Sin{1}. I wish I had read it back then. It would have saved me so much pain in my battle against sin.

download-podcastSo I want to help you in that same way by sharing some of Owen’s key insights in the battle against sin.

Let’s begin with the title. Mortification, what does that word mean? Broadly speaking, it means to kill or put to death. The Latin root from which this English word is derived, “mort-“ or “mors” means death. Mortificare—to kill.{2} Other examples of this root include mortuary, mortician, and mortgage.

Simply put, mortification means death, but note the dictionary also lists “shame” and “humiliation” as definitions as well. So mortification involves death. More to the point, Owen wants you to kill sin. More importantly, he makes a case that Scripture commands you to kill sin.

This message today is not for everyone. It’s only appropriate if you believe in Jesus. Early in the work Owen gravely warns those
who would mortify sin, but do so without first believing in Jesus.

I would warn you as well. Please don’t sit here and read another minute if you have not put your faith in Jesus Christ for your righteousness, for your salvation. If you’re reading this right now and have never made a confession of faith, and you’re ready, please do so now. Just talk to God and tell him you believe that Jesus is Lord, that He died for your sins, was buried, and raised from the dead, and you are putting your trust in Him. Then tell someone you know who already believes. It will be the most important thing you do, ever.

If you’re still reading, then let’s press on. Owen discusses at length what it means to kill sin, how to do it effectively, and why you should do it.

But before we jump in, remember John Owen was a 17th century English pastor and theologian. This is not his first book, and at the time he composed it, he was Vice-Chancellor at the University of Oxford. Owen has academic credentials. But this book is more devotional than academic. Owen draws from personal experience. It is not merely intellectual. He meant for it to be practiced.

What is Mortification?

John Owen wrote The Mortification of Sin in England in 1656. Mortification means death, or in this case to kill. . .sin. That’s what we covered in the previous section. This matters because your life is at stake here. In chapter two, Owen warns us with this now famous quote, “Be killing sin or it will be killing you.” That is probably the most famous quote from that book.

Did you catch the significance of that quote? Sin will kill you. That’s why this is a big deal. That’s why this matters. That’s also why sin’s presence requires such a drastic response. It must be killed. James tells us that “[S]in when it is fully grown brings forth death.”{3}

Your best option—the most effective option—your only real option is to kill sin. Just like John Owen said. Kill it. Or it will kill you. Because trust me. It will kill you—in every way: physically, spiritually, emotionally, intellectually—every way.

Owen quickly reminds us this is impossible in a complete, ultimate, or perfect sense, until Jesus comes back, not before.{4} So until then we mortify sin.{5}

Now let’s talk about mortification. Let’s talk about killing sin. What exactly does that mean? Sin is an abstract thing, not a biological organism. How do you kill an abstract thing? Owen’s instruction is clear: “utterly destroy it” or, make it cease to be.

Owen defines the process of mortification three ways: sin gets weaker, you fight against it constantly, and you have full success over it.{6}

So then mortification means to weaken sin, or drain it of its power. It means the desire to sin decreases in degree, frequency, and
quality. That comes as you “crucify the flesh with its passions and desires,” as we read in Galatians 5:24.

Mortification also means to fight sin constantly. You have an enemy. Employ any means necessary to destroy his work. The contest will be vigorous and hazardous.

Finally, mortification is success against sin in any given moment. This isn’t merely resisting temptation. Owen has more in view here; it is recognizing temptation, bringing it before Christ, pursuing sin to its root, and conquering it in Jesus’ strength.

Before we discuss how to do this, for clarity let’s talk about how not to mortify sin.

How NOT to Mortify Sin

Mortification means to kill, and the point of John Owen’s book The Mortification of Sin is to kill sin. Nothing short of your life is at stake here since sin always leads to death.{7}

Sin is not to be trifled with. It cost Jesus His life.

Owen himself covers what mortification is NOT in the book, before he defines what it is. So now we will follow his lead.

Mortification is commonly mistaken. It is tricky to identify properly. Four things frequently masquerade as mortification, when they are in fact not. These four are: faking it, having a calm disposition, cross-addiction, and behavior modification.

Faking it, the first instance of false mortification, is making yourself look good on the outside, instances where outward signs of sin are obvious—compulsive spending, for example. You may choose not to buy something the next time you’re tempted, but that outward choice is not the root of sin. The root is inside. It goes deeper.

The root is the belief that material will fill that void inside. Owen further points out hypocrisy as a real danger here. Not only did you not mortify the sin, you are now making it look as if you have.

Mortification is also not simply a calm disposition. Some sins are obvious, visible, even violent in nature. In these cases if you become more calm, more quiet, more gentle, it could appear on the outside as if the sin is gone. In fact it is not. Owen reminds us that mortification is more than a simple change in disposition.

Mortification is also not replacing one vice for another. For example, if the presenting sin is addiction to pornography, keeping yourself from erotic material may appear as victory unless you pick up the bottle. Now you simply exchanged pornography for alcohol. You exhibit a cross-addiction. This, too, is not mortification.

Mortification is also not mere change in behavior. Surely you have made a big change before—created a new habit, lost weight, something, even a New Year’s resolution. You can force the behavior for a while—maybe even through February! You can make yourself do what you’ve resolved. But eventually, that old habit creeps back; unless some real changes are made, it’s merely a shift in behavior. This also is not mortification.

What is mortification, then? How do you do it?

How to Mortify Sin

After all this preliminary discussion, you probably want to know how you can kill sin, conquer it, and be victorious, because if you don’t it will kill you, as Owen himself says in the book.

Here’s the bad news, though. You can’t mortify your sin. You will have no victory over sin by employing any method I recommend to you. Now, don’t despair! This doesn’t mean you can’t experience victory! God forbid. Rather, it is God’s will for you to find victory over the curse of sin. What I mean here is that mortification is not something you do. It is instead something God does, namely the Holy Spirit.

Only the Holy Spirit can mortify sin, kill sin in the flesh. Only He is strong enough to put to death the old man.

So what do you do, then? Here are Owen’s words. “Set faith at work on Christ for the killing of thy sin. His blood is the great sovereign remedy for sin-sick souls. Live in this, and thou wilt die a conqueror. Yea, thou wilt, through the good providence of God, live to see thy lust dead at thy feet.”{8}

The way to mortify sin is to set faith at work. Put your faith to work. Believe in the work Jesus did on the cross.
His sacrifice is your remedy. That’s how you kill sin—you don’t. You believe in the power of Christ’s atoning sacrifice on the cross, and let Christ kill it for you.

It’s freeing really. Would you want the responsibility of killing the broken flesh within you? I don’t. Owen goes on to add two more
points of substance. First “fill your soul” with the provision of Christ. I might call that meditation. Meditate on Christ. Fill your mind with His provision.

The second point is to expect relief in Christ. Owen reasons that if Christ’s blood is enough to make you righteous—and if the Spirit is strong enough to mortify your flesh, then expect it’s going to happen. It may not be instantaneous. Anyone who’s been walking with Christ for some time will affirm this. It’s a slow and difficult, often painful process, but definitely a good one.

So that is how you mortify sin. You don’t. You let the Spirit do it. Your job is to believe by faith.

Conclusion

What have we learned so far? If you are following in the footsteps of Jesus, you need to mortify, or put to death, sin in your life. If you don’t it will kill you.

This is not a popular message. I admit. Sin is not a fun topic. But Scripture is clear. Sin must be put to death. Owen’s book, while
dating over three hundred years back, could be neither more timely nor more appropriate for you today.

Owen admonishes the sincere believer to kill indwelling sin without delay. He warns the unbeliever this is impossible without Jesus Christ. Jesus is absolutely essential to the success and continued process of mortification. To do otherwise is the “soul and substance of all false religion in the world.”{9}

If you believe in Jesus and you are stuck in your sin, maybe you’re trapped in addiction, this book is for you. Mortify sin.

“Set faith at work on Christ for the killing of thy sin.”{10} You believe in His Son for salvation. Believe Him now for the deliverance of your soul from the power of indwelling sin.

It is not easy. You will struggle every day against sin. The bad news here is that you carry the problem with you. Your flesh is broken. It remains unregenerate until the day of Christ. Your soul is secure eternally by the blood of Christ, and one day you will receive a gloriously new body. But for now, we struggle.

But consider Jesus’ promise in that struggle: “I have told you all this so that you may have peace in me. Here on earth you will have many trials and sorrows. But take heart, because I have overcome the world.”{11}

Mortification is not for the faint of heart. But it is good. Your sin does not define you. God does. And he says you are fearfully and wonderfully made.{12} He paid the price of your sin. It was an awful lot. But he loves you that much.

Trust him today. Trust in his Word. And trust in the community of saints He provided for you. Confess your sin to them today. Do you
want to fully live? Then kill sin.

Notes

1. John Owen, The Mortification of Sin. (Ross-shire, UK: Christian Focus Publications, Geanies House), 1996.
2. American Heritage Dictionary, 2000.
3. James 1:15.
4. 1 Corinthians 15:50-54.
5. Colossians 3:5.
6. Owen, p.64.
7. James 1:15; Proverbs 14:12; Genesis 2:17.
8. Owen, p.161.
9. Ibid., p.23.
10. Ibid., p.161.
11. John 16:33.
12. Psalm 139:14.

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