My wife (bless her heart) put together a synopsis of the sermon manuscripts on John Piper’s three part series, “How to Kill Sin.” It has been so beneficial for both of us and our souls. We thank God for Dr. Piper, the spiritual physician.

How to Kill Sin
A Synopsis of John Piper’s Sermon Series

Romans 8:10-17

If Christ is in you, though the body is dead because of sin, yet the spirit is alive because of righteousness. 11 But if the Spirit of Him who raised Jesus from the dead dwells in you, He who raised Christ Jesus from the dead will also give life to your mortal bodies through His Spirit who dwells in you. 12 So then, brethren, we are under obligation, not to the flesh, to live according to the flesh – 13 for if you are living according to the flesh, you must die; but if by the Spirit you are putting to death the deeds of the body, you will live. 14 For all who are being led by the Spirit of God, these are sons of God. 15 For you have not received a spirit of slavery leading to fear again, but you have received a spirit of adoption as sons by which we cry out, “Abba! Father!� 16 The Spirit Himself testifies with our spirit that we are children of God, 17 and if children, heirs also, heirs of God and fellow heirs with Christ, if indeed we suffer with Him so that we may also be glorified with Him.

Life is War

The Christian life requires warfare against sin. Not the sins of others – our sin. Until you believe that life is war – that the stakes are your soul – you will probably just play at Christianity with no blood earnestness and no vigilance and no passion and wartime mindset. If that is where you are this morning, your position is very precarious. The enemy has lulled you into sleep or into a peacetime mentality, as if nothing serious is at stake.

Matthew 11:12 – “From the days of John the Baptist until now the kingdom of heaven suffers violence, and violent men take it by force.� Do you want to enter the kingdom of heaven? Take it violently! But violence against whom, or against what?

Matthew 18:8 – Jesus’ answer: “If your hand or your foot causes you to stumble, cut it off and throw it from you; it is better for you to enter life crippled or lame, than to have two hands or two feet and be cast into the eternal fire.� If we want to enter life, we need to take it violently. Jesus calls us to cut off our hand or our foot if we must to keep from stumbling. It’s a picture of the most radical kind of assault on our own sin. Not the sins of our children or husbands or Muslims or parents or in-laws, but our sins. Jesus calls us to a violence against all the impulses in ourselves that causes us to have a meanness against other people. It’s a violence against all lust in ourselves, and enslaving desires for food or caffeine or sugar or chocolate or alcohol or pornography or money or the praise of men and the approval of others or power or fame. It’s a violence against the impulses in our own soul toward racism and sluggish indifference to injustice and poverty and abortion.

Whining about my sin, complaining about my struggle with sin does nothing! I have to kill my sin.

Romans 8:12-13 says, “So then, brethren, we are under obligation, not to the flesh [literally: we are debtors not to the flesh], to live according to the flesh – for if you are living according to the flesh, you must die; but if by the Spirit you are putting to death the deeds of the body, you will live.� If we want to inherit life and not death, Paul says we must not be the debt-paying slave of the flesh – that old rebellious, insubordinate, self-sufficient nature we all have (Romans 8:7). We owe the flesh nothing but enmity and war. We must not give into the flesh as if we owe it anything. Don’t dally with your destroyer. Don’t be a debtor to your destroyer. Get out of debt to the flesh, don’t pay for your own destruction.

People don’t go to hell because of Satan. People go to hell because of sin.

John Owen on Mortification of Sin

John Owen wrote an 86 page book called Mortification of Sin in Believers. “Mortify� means “kill� in 17th century English, not “embarrass� or “shame� as it means today. The whole book is an exposition of this verse, Romans 8:13. He put it like this: “Be killing sin or sin will be killing you.�

“This book will keep you from sin, or sin will keep you from this book.�

Practical Questions to Answer from this Text

1. What are “the deeds of the body� when Paul says, “If by the Spirit you kill the deeds of the body, you will live�? Not all the deeds of the body are to be killed if the body is supposed to be an instrument of righteousness. So which deeds are we to kill?

2. What does killing them mean? Do they have life that we should take away? What will killing them involve?

3. What does “by the Spirit� mean? The Spirit is himself God. He not a lifeless instrument in our hands to wield as we wish. I am in His hand, aren’t I? How am I to understand this killing of sin “by the Spirit�?

4. Does this threat of death mean that I can lose my salvation? Verse 13a: “If you are living according to the flesh, you must die.� The death this verse warns about is something more than a physical death, something that happens only to some and not to others. Can we die eternally if we have been justified by faith? If so, what becomes of our assurance, and if not why does Paul threaten us all with death if we live according to the flesh and tell us to be about the business of killing sin?

Answers to these Questions

1. What are the Deeds of the Body that we are to kill?

a. Romans 6:14, “Do not present your members [=your bodies] to sin as instruments for unrighteousness, but present yourselves to God as those who have been brought from death to life, and your members to God as instruments for righteousness.� The deeds of the body that we are to kill are those deeds that we are about to do (you kill them before they happen) when our bodies are instruments of unrighteousness.

b. Romans 6:12, “Do not let sin reign in your mortal body so that you obey its lusts.� When the mortal body is taken captive by sin and made to obey lusts, then and there we see “deeds of the body� that should be put to death.

c. Romans 6:6, “Our old self was crucified with Him, in order that our body of sin might be done away with, so that we would no longer be slaves to sin.� Killing the sinful actions of the body happens in union with Jesus Christ by faith alone. You are already dead to sin and alive to God. What you are doing when you put to death the deeds of the body is becoming in practice what you are in Christ. He breaks the power of cancelled sin. We can only kill the sin that has already been killed when we were killed in Christ.

2. What is Putting to Death?

a. The putting to death is cutting off the life-line, the blood flow. Deeds of the body are the instrument of the sin that’s in our hearts. Matthew 15:18-20, “The things that proceed out of the mouth come from the heart, and those defile the man. For out of the heart come evil thoughts, murders, adulteries fornications, thefts, false witness, slanders. These are the things which defile the man; but to eat with unwashed hands does not defile the man.�

b. The root of the deeds of the body that has to be killed is the flesh that is hostile to God and unwilling and unable to submit to him. Romans 8:7 says, “The mind set on the flesh is hostile toward God; for it does not subject itself to the law of God, for it is not even able to do so.� Flesh is the great enemy here because it is insubordinate and hostile to God.

3. How do you do this “by the Spirit�?

STEP ONE: Set Your Mind on the Things of the Spirit
Romans 8:5, 6 says that putting to death the deeds of the body by the Spirit involved “setting the minds on the things of the Spirit�. You don’t just look at the temptation or the idol and say NO. You do that! But if you are going to put it to death by the Spirit, you have to do more: you direct your mind, your heart, your spiritual focus another way, namely to the “things of the Spirit�.

STEP TWO: Set Your Mind on the Words of God and the Realities They Stand For

What are “the things of the Spirit�? 1 Corinthians 2:13,14 says the things of the Spirit are the words of God spoken by the apostles. So putting to death the deeds of the body “by the Spirit� is to “set your mind on the things of the Spirit� which means embracing the words of God and the reality they point to, spoken by His inspired spokesmen.

Ephesians 6:17 says the Word of God is “the sword of the Spirit�. Swords are used for killing. And that is what we are to do “by the Spirit� in Romans 8:13. Kill the deeds of the body by the Spirit, that is by fixing your mind on “the things of the Spirit�, which means welcoming and embracing the “word of God� in your mind and heart, that is, by taking the Sword of the Spirit which is the deadly sword for sin-killing.

STEP THREE: By Hearing with Faith, not Works of the Law

What do you do to bring the power of the Spirit by the Word of God into vigorous, sin-killing action? Galatians 3:5, “So then, does He who provides you with the Spirit and works miracles among you, do it by the works of the Law, or by hearing with faith?� By hearing with faith. The Spirit is supplied to us for the miraculous killing of sin “by hearing with faith�.

There is a paradox here that YOU have to kill sin. Paul says you must do it. “You put to death the deeds of the body.� But on the other hand, it says, you do it “by the Spirit.� The Spirit is the decisive killer. So the paradox is that you do it in such a way that it is He who does it. That is the difference between the Christian life and a moral self-improvement program.

Why “by hearing with faith� and not just “by faith�? The answer is that the sword of the Spirit is the word of God, and it’s the word that you hear and believe. When the word of God – the Sword of the Spirit – is heard and believed, the Spirit is moving with vigorous, sin-killing action.

The connection between the Holy Spirit and you is the word of God and faith. They are like socket and plug. When the plug of your faith goes into the socket of God’s Word, the Holy Spirit is flowing. And when he flows, he kills sin.

We Kill Sin the Same Way We Get Saved

Ephesians 2:8, 9 says, “By grace you have been saved through faith; and that not of yourselves, it is the gift of God; not as a result of works, so that no one may boast.� Faith, not works, is the way we are made right with God, and faith, not words, is the way we engage the Holy Spirit to kill sin. This is how you become a Christian, and this is how you grow as a Christian.

To become a Christian, you believe the promises of God, like Romans 10:12 or John 3:16. And to fight sin as a Christian, you believe the promises of God like “I will never leave you nor forsake you� Hebrews 13:5. When Christ died for us, he bought with His blood both justification and sanctification. Both are obtained by faith. We begin and end by trusting the gift of imputed righteousness and the power of God’s grace to kill sin and impart practical righteousness.

The Glory of Christ is at Stake in Living this Way

Why can’t we just pray that God would kill the sin in my life? Prayer is crucial, but it is not the sum total of what “put to death the deeds of the body by the Spirit� means. Paul says the Spirit is supplied to you by hearing with faith. Not just asking, but hearing, and not just hearing, but by hearing with faith.

Killing sin in our lives must glorify Jesus, and Jesus is glorified when we kill sin by the Spirit, that is, by hearing and believing the promises that he bought and secured by his own blood which is at root the gospel of Jesus Christ.

If we merely pray and ask God to kill our sin, without hearing the gospel of Christ or any of its promises, Christ would not be honored by our holiness. So God designs our sanctification to magnify His Son, which doesn’t happen by prayer alone but by hearing the Christ-exalting, blood bought promises of God and believing them as we ask God to kill our sin.

4. Does the Threat of Death Imply We Can Lose Our Salvation?

No. Someone who is justified by faith alone apart from works of the law cannot die in this sense of eternal death. Romans 8:30, “And those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified.� If you have been justified by faith you will be glorified. You’ll be brought to eternal life and glory. The chain will not be broken: Predestination, calling, justification, glorification.

So, putting to death the deeds of the body by the Spirit – the daily practice of killing sin in your life – is the result of being justified and the evidence that you are justified by faith alone apart from works of the law. If you are making war on your sin, and walking by the Spirit, then you know that you have been united with Christ by faith alone. And if you have been united to Christ, then his blood and righteousness provide the unshakable ground of your justification.

Putting to death the deeds of the body is not the way we get justified, it is one of the ways God shows that we are justified. If we aren’t killing sin in our lives, if growth in grace and holiness mean nothing to us, then there is no compelling reason for thinking that we are united to Christ by faith or that we were therefore justified. We are probably not Christians after all and never were.

Killing sin every day in our lives is the way that justified sinners live.