Why Not Sin?
As a Christian, why not sin? We could give a myriad of answers to that question. However, the best answer is supplied by Paul in Romans 6. Paul could have talked about the misery that sin brings, the pain that it inflicts upon others, the consequences which flow from it, or the penalty that Christ had to pay for it. But that is not where he first turns. He wants Christians to understand that we cannot easily entertain sin, because of our identity.
In Romans 5, Paul focuses on justification. In Romans 6, he points out that our sanctification cannot be separated from our justification. Those who have been forgiven their sins in Christ are to live in light of having been forgiven. Paul addresses this by pointing out that we are in union with Christ. Look at the language in Romans 6:3, "Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death?" Verse 4, "We were buried therefore with Him." Verse five, "For if we have been united with him." Verse 6, "We know that our old self was crucified with him." Verse 8, "Now if we died with Christ, we believe that we will also live with Him." As Christians, we have been united with Christ. We are one with Him. In fact, that is what makes us Christians. Paul would have us to understand that our union with Christ marks every aspect of our salvation. That is, by faith we have been united with Christ for our justification, sanctification, and glorification. These cannot be separated anymore than Christ can be separated. Christ cannot be ripped asunder; therefore, we cannot rip sanctification from justification. This has great ramifications.
We have nothing apart from Christ. We have no justification, peace, forgiveness, sanctification, righteousness, holiness, Heavenly Father, or indwelling Spirit apart from Christ. Every part and parcel of our salvation is ours, because we are in Christ. As Anthony Lane put it, "Until we are united with Christ what he has achieved for us helps us no more than an electricity main supply that passes our house but is not connected to it." Union with Christ is our identity.
This leads Paul to ask the question that he does in Romans 6:2, "How can we who died to sin still live in it?" Before we came to know Christ, we were dead in sin. Ephesians 2 tells us, "You were dead in the trespasses and sins in which you once walked." Now as a Christian, Paul declares that we are not dead in sin, we are dead to sin. This is what Paul wants Christians to understand above all else in response to the question of why we should not continue in sin: you have died to sin, dear Christian. It has happened. That is our identity in Christ. That is who we are.
When we became a believer by grace through faith in union with Christ, we died to sin. It is not a progression that Paul has in mind, though it is true that we are to die to sin every day. It is also not a future reality that he is looking to, though it is true that we will know freedom from sin more in heaven than we have ever experienced on this earth. Rather, what Paul is pointing out in Romans 6 is that it is a historic reality for the Christian. We have died to sin. It has already occurred in our past by virtue of our being united with Christ. John Murray aptly explained this by suggesting that when we came to saving faith in Christ there was "a definitive breach with sin."
Look at how desirous Paul is for us to understand this in just the first 14 verses of Romans 6. Verse 2, "How can we who died to sin still live in it?" Verse 3, "all of us who have been baptized into Christ Jesus were baptized into his death." Verse 4, " buried with him by baptism into death, just as Christ was raised from the dead." Verse 5, "united with him in a death like his." Verse 6, "crucified, brought to nothing." Verse 8, "died with Christ." Verse 9, "being raised from the dead will never die again. Death no longer has dominion over him." Verse 10, "For the death he died." Verse 11, "consider yourselves dead to sin."
Death is everywhere in these 14 verses. Even the most uninformed reader can see that Paul is making a single point. He is declaring with passion, "Don't you understand, when you were united with Christ by grace through faith, you were united with Him in His death?" Christ died. And by our union with Him, we died with Him. He died, so we died. That old life of mine, that unregenerate man that I was, that man trapped in sin, steeped in sin, dominated and controlled by sin, is dead. And so it is for you, if you are in Christ. Sin's power and authority has already been broken in your life.
Sin is no longer our king. It is no longer our sovereign. We need not follow its dictates. It cannot command us. We have been set free to serve a new Lord, a better Lord. Sin no longer sits upon the throne of our hearts, grace does in the person of King Jesus. That is the principle reason we are not to sin. Our identity has been changed. Giving ourselves over to sin is harkening back to an old lord, an impostor, a realm to which we no longer belong. Sin that grace may abound? By no means!
John Murray "Definitive Sanctification" - an audio lecture
John Murray Collected Writings of John Murray vol. 2 (Banner of Truth)
John Murray Redemption Accomplished and Applied (Eerdmans Publishing)
Joseph Pipa "Definitive Sanctification" - a lecture given at the 2001 GPTS Theology Conference
Sinclair Ferguson "Grace Abounding, Sin Continuing?" - (audio sermon)
Sinclair Ferguson "Do You Consider Yourself Dead To Sin?" - (audio sermon)
Sinclair Ferguson "Sin: A Dominion Ended; A Reign Rejected" - (audio sermon)
Sinclair Ferguson "Union with Christ: Mind-Renewing Foundations" - a lecture given at the 2014 Desiring God Pastor's Conference