Tim Challies dug up some interesting quotes from Jerry Bridges’ work, The Discipline of Grace. These two quotes deal with the issue of why Christians still sin even though we have “died to sin” (Ro 6). Before explaining what it means to die to sin, Bridges explains how it is that we became sinners to begin with:

Federal headship or representative capacity is somewhat illustrated by the concept of power of attorney. A friend of mine wanted to refinance the mortgage on his house to take advantage of lower interest rates. When the date for the closing was finally set, he realized that he and his wife would be out of the country at that time. He asked if I would represent them at the closing, and I agreed, so he and his wife executed a power of attorney authorizing me to act on their behalf.

I went to the closing and, as my friends’ legal representative, signed all kinds of papers. When I signed those documents it was just as if they had signed them. When I signed the promissory note to pay a certain amount each month, that act was as legally binding on them as if they had signed the note, because I was acting as their legal representative. In like manner, Adam was our legal representative in the garden, and when he sinned, his action was as binding on us as if we had sinned personally.

We may object that we did not appoint Adam as our representative in the garden. To do so is futile, however, for in our objection we are actually complaining against God. It should be enough for us to know that God, the Sovereign Creator of the universe and the One in whom we live, and move, and have our being, appointed him.

Thankfully, as Challies points out, Adam was not the only federal representative. God appointed Christ Jesus as the second federal head, the “last Adam” (1 Co 15.45). And as Paul explains in Romans 5, just as “by the one man’s disobedience the many were made sinners, so by the one man’s obedience the many will be made righteous.” (Romans 5:19 ESV)

Once federal representation is understood, the meaning of what it means to be “dead to sin” is better understood. From Bridges:

To die to sin then means, first of all, to die to its legal or penal reign and, secondly, as a necessary result, to die to its dominion over us…There is no such thing as salvation from sin’s penalty without an accompanying deliverance from sin’s dominion. This obviously does not mean we no longer sin, but that sin no longer reigns in our lives.

How did we die to sin? We have already noted that we died to sin through our union with Christ. Paul said in Romans 6:10 that Christ died to sin, and in verse 8 he said we died with Christ. That Christ died to sin is a rather startling but wonderful statement. Christ did not die to the dominion of sin, as He was never under it. However, when He was made sin for us (2 Corinthians 5:21)—that is, when He was charged with our sin—He did come under its legal reign and was made subject to its penalty.

When Jesus died, He died to the legal reign of sin. Through our federal union with Him in His death, we, too, died to the legal reign of sin. But because the legal reign and the practical dominion of sin in our lives are inseparable, we died not only to its legal reign but also to its corrupting dominion over us. Hallelujah! What a Savior we have who was able to not only free us from sin’s penalty but also from its dominion.

The question arises, however, “If we died to sin’s dominion, why do we still struggle with sin in our daily lives?” When Paul wrote, “We died to sin; how can we live in it any longer?” he was referring, not to the activity of committing sins, but to continuing to live under the dominion of sin. The word live means to continue in or abide in. It connotes a settled course of life. To use Paul’s words from Romans 8:7, “The sinful mind [one under sin’s dominion] is hostile to God. It does not submit to God’s law, nor can it do so.” But the believer who has died to sin’s reign and dominion delights in God’s law. The believer approves of it as holy, righteous, and good (Romans 7:12), even though he or she may struggle to obey it.

We must distinguish between the activity of sin, which is true in all believers, and the dominion of sin, which is true of all unbelievers. Sinclair Ferguson has written, “Sin is not primarily an activity of man’s will so much as a captivity which man suffers, as an alien power grips his soul. It is an axiom for [John] Owen [whose teaching Ferguson is summarizing] that while the presence of sin can never be abolished in this life, nor the influence of sin altered (its tendency is always the same), its dominion can, indeed, must be destroyed if a man is to be a Christian.

Therefore a believer cannot continue in sin. We no longer live in the realm of sin, under its reign and practical dominion. We have, to use Paul’s words, died to sin. We indeed do sin and even our best deeds are stained with sin, but our attitude toward it is essentially different from that of an unbeliever. We succumb to temptations, either from our own evil desires (James 1:13), or from the world or the Devil (Ephesians 2:1-3), but this is different from a settled disposition. Further, to paraphrase from Ferguson on John Owen, our sin is a burden that afflicts us rather than a pleasure that delights us.

I found all of this very helpful. By making the distinction between the complete removal of sin versus being set free from the dominion and reign of sin, the presence of sin is accounted for. But, it doesn’t end there. The same Paul who spoke of being set free from the dominion of sin, also looked forward to a complete deliverance from it. Being “dead to sin” does not mean that we will not struggle with sin; but even our struggling will one day come to an end.

So then, brothers, we are debtors, not to the flesh, to live according to the flesh. For 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. For all who are led by the Spirit of God are sons of God. For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, “Abba! Father!” The Spirit himself bears witness with our spirit that we are children of God, and if children, then heirs—heirs of God and fellow heirs with Christ, provided we suffer with him in order that we may also be glorified with him.

For I consider that the sufferings of this present time are not worth comparing with the glory that is to be revealed to us. For the creation waits with eager longing for the revealing of the sons of God. For the creation was subjected to futility, not willingly, but because of him who subjected it, in hope that the creation itself will be set free from its bondage to corruption and obtain the freedom of the glory of the children of God. For we know that the whole creation has been groaning together in the pains of childbirth until now. And not only the creation, but we ourselves, who have the firstfruits of the Spirit, groan inwardly as we wait eagerly for adoption as sons, the redemption of our bodies. For in this hope we were saved. Now hope that is seen is not hope. For who hopes for what he sees? But if we hope for what we do not see, we wait for it with patience. (Romans 8:12-25 ESV)

And,

Now may the God of peace himself sanctify you completely, and may your whole spirit and soul and body be kept blameless at the coming of our Lord Jesus Christ. He who calls you is faithful; he will surely do it. (1 Thessalonians 5:23-24 ESV)

Have nothing to do with any heretical teaching that lessens Christ’s work of salvation by arguing that forgiveness of sin is the end all, be all. We are forgiven and set free from sin’s dominion in order that we will one day defeat sin entirely; the effects of which will benefit the whole man!