The passage
      v15. As in verse 1, Paul outlines a criticism that was made against him by law-bound believers. They had argued that his teaching on justification (the free gift of right-standing before God by faith, apart from obedience to God's law) promoted careless-living in the Christian life, not right-living. The implication, they suggested, of Paul's teaching, was that since believers live under the canopy of God's saving grace (his covenant mercy), rather than under the direction of his law, then obviously a bit of unrestrained sin, from time to time, is of little importance. "No way", says Paul. In the rest of the passage Paul sets out to make the point that a person who stands right before God is naturally orientated to live in a way that is honoring to God. A believer's acceptance of justification by faith promotes right-living, not careless-living.
      v16. The logic of Paul's argument is simple; a slave is subject to their master. There are two slave-masters; we may be subject to one master, or subject to the other. If our master is sin, then our slavery is to sinning with death as its end. If our master is God, then our slavery is to obedience with a life lived to God ("righteousness") as its end. Paul's language is a little confusing since he has us obeying obedience, but his point is clear enough.
      v17-18. Paul is thankful that his readers have properly heard the gospel and therefore are transferred from the possession of sin (a state of rebellion against God) to the possession of "righteousness" (a state of right-living for God). A person who puts their trust in Christ stands eternally right in the sight of God. Such a person, through the renewing power of the indwelling Spirit, begins to express that righteousness in their lives.
      v19a. Paul here qualifies his use of the slavery image. A Christian's relationship to God is not at all the unjust, humiliating and degrading, as is slavery; it is a service of perfect freedom - liberation.
      v19b. So, as free men and women, standing approved before God, Paul encourages us to enslave ourselves, not to "ever-increasing wickedness", but rather to "righteousness", right-living, thus shaping in our lives the "holiness" we possess in Christ. In simple terms, "be what we are." Here then is the nub of Paul's argument: "Righteousness leading to holiness" is a natural by-product of a believer's justification by faith. Willy-nilly sinning is not the fruit of justification.
      v20. On the other hand, a person who is a slave to sin (eg. Paul's law-bound critics who seek God's approval by obedience to the law and who are therefore bound by sin and the curse of the law) are quite unable to live a righteous life.
      v21. As slaves to sin, their end was death.
      v22. As the "slaves to God", those who have been set free from sin, set free from its condemnation and its power under the law, the return we get leads to sanctification and ultimately eternal life.
      v23. In summary then, the end of sin is death, the end of grace, through faith, is life.

It's all too simple
      Believers have always found it difficult to accept a full understanding of the doctrine of justification by faith. The doctrine seems to promote sin. If the believer has already been credited with perfect righteousness for eternity, if all their good works, all their faithfulness to the law of God, cannot in any way either gain or maintain their salvation, nor in any way please God or progress their Christian life, then why worry about sin? why try to do good? why strive to live a righteous life? Why not sin that grace may abound? v1. Why be fussed by a few sins here or there? v15.
      The truth is that not only does our faith in Christ gain God's eternal forgiveness and approval for us, but it results in obedience rather than disobedience. It results in faithfulness, good works. A believer is blessed with the indwelling presence of Christ. His compelling love, when activated through the instrument of faith, leads the believer, not to a life of sin, but to a life of grateful service to God. Sure, we will fail, and sometimes fail badly, but our whole orientation will be toward faithful service, to be that person we are already in Christ.

      As noted in previous studies, Paul may have used a chiastic structure (a ring composition) for his argument in chapters 5-8. It is important to consider the possibility as it can improve our understanding of the flow of Paul's argument:
        A. Assurance of future glory, 5:1-11;
          B. Basis for assurance - the work of Christ, 5:12-21;
            C. The problem of sin, 6:1-23;
            C'. The problem of sin and the law, 7:1-25;
          B'. Basis of assurance - the work of Christ through the Spirit, 8:1-17;
        A'. Assurance of future glory, 8:18-39.

v15
      ti oun "what then?" - Possibly, "what shall we say", BDF argues for an ellipsis. Introducing a similar false inference to that of v1, an inference used by Paul's nomist brothers to counter the notion that the Christian life is lived by grace through faith rather than by a faithful adherence to the law, "what inference are we to draw?", v1, Barclay. The inference is that if salvation is all of grace, then sin doesn't matter, but we all know that sin does matter to God, so obviously the "all of grace" theory is flawed.
      aJmarthswmen (aJmartanw) aor. sub. "shall we sin" - may we sin. A deliberative subjunctive. Aorist indicating a single act of sin, "seeing we are saved by grace, what's one sin here or there?"
      uJpo nomon "under law" - "Ruled by law", CEV; "slaves", Williams; "under the authority of", Weymouth... is a bit too strong, but "guided by law" is a touch weak. The argument of Paul's opponents is not focused on conversion, it's not over how a person becomes a Christian. The argument is over the Christian life and the part the law plays in the business of living for Christ. In simple terms, we might say, it's an argument over sanctification. Paul's opponents, the nomists, argued that a believer's standing in the presence of God is confirmed and progressed through an adherence to the law (probably including the law of Christ), whereas Paul argues that a believer's standing wholly rests on the covenant faithfulness of God (it is a "gift", a "grace" of God) appropriated by faith. Although sin is irrelevant when it comes to our standing before God, it does not "abound" because it is irrelevant. Paul's argument is that a believer, standing right in the presence of God, will tend toward "holiness", rather than sinfulness.

v16
      ouk oidate "don't you know" - do you not know. "You know well enough", NEB. paristanete (paristhmi) "offer" - offer in the sense of place beside such as in a sacrifice. The idea is not of being enslaved, but of our offering ourselves as a slave to one of two masters. "Surrender yourselves", TEV.
      eiV uJpakohn (h) "to obey" - to/for obedience. In the sense of be in subjection to. "You belong to the power you choose to obey", Phillips. The two masters we may belong to are either "sin" or "God", under which masters we live in "sin / ever increasing wickedness" or "obedience / holiness."
      htoi .... h "whether ...... or" - This is the only example of this construction in the New Testament and implies that there are only two alternatives to choose from.
      aJmartiaV (a) "[slaves to] sin" - Here surely the active state of rebellion against God, ie. capital "S" sin, Moffatt.
      uJakohV "obedience" - This final use of the word in the verse is problematical. What does it mean to belong to obedience, having chosen to be subject to obedience? Presumably the obedience is that which naturally flows from a slavery to God, in which case Paul has compressed his argument here. So, as slavery to sin issues in sin, so a slavery to God issues in obedience. The difficulties still remain because the end of "obedience" is "righteousness", as the end of "sin" is "death". Surely not "results in being put right with God", TEV, ie. justification. Moo suggests that "righteousness" here is "moral righteousness, conduct pleasing to God", and given the context, this seems more likely.

v17
      hte (eimi) "you used to be" - Imperfect underlining what was the case.
      uJphkousate (uJpakouw) aor. "you [wholeheartedly] obeyed" - Aorist pointing to a decisive act of believing the gospel, turning to Christ.
      ek kardiaV (a) "wholeheartedly" - from heart. "Voluntary and sincere", Hodge; "without reservation", JB.
      tupon (oV) "form" - form or type. The gospel, the Christian teaching concerning Christ, "the pattern of teaching", NEB.
      eiV oJn paredoqhte (paradidwmi) aor. pas. "to which you were entrusted" - to which you were committed, delivered over to. The passive indicating the stress upon God's action in delivering the readers over to the teaching, although an active sense reads better, "that you received", Goodspeed.

v18
      eleuqerwqenteV (eleuqerow) aor. pas. part. "have been set free" - having been set free, released. In what sense is a believer "set free" from sin? Some commentators stress the moral sense, so "set free from the power of sin." It is true that since a believer is no longer under the law, sin has lost it's power to control us. The law empowers sin, makes it more sinful, so without the law, sin's power is reduced. That's not to say we still don't sin. Yet, it is also possible that Paul has in mind a legal sense, "set free from the condemnation of sin", a condemnation that ends in "death". Of course, both ideas may be present.
      th/ dikaiosunh/ (h) "[have become slaves] to righteousness" -[you were enslaved] to the righteousness, justice. Enslaved to "righteousness" can be understood in a moral sense, "to justice", "slaves of right-doing", Williams, or understood in a legal sense as "enslaved to right-standing / righteousness before God." We are constantly faced with this choice in the passage before us. The sense is likely to be moral in that Paul's argument is that when a believer possesses righteousness before God (ie. has accessed, by faith, "the righteousness of God", his covenant faithfulness) then such possession prompts righteousness, justice, right-living, ... under God.

v19
      anqrwpinon legw "I put this in human terms" - humanly I speak. I speak "as people do in daily life", BAGD.
      thn asqeneian (a) "weak [in your natural selves]" - weak [in your flesh]. Meaning their difficulty in grasping the significance of what Paul is saying. Other possibilities include, moral weakness and the weakness of their pre Christian state.
      paresthste (paristhmi) aor. "offered" - Aorist indicates the completeness of the action, so "wholeheartedly offered."
      melh (oV) "parts" - body. Not quite parts, but rather an individual member or part which represents the whole. Therefore "body" is better, or even just "yourself" - "just as you offered yourselves in slavery to impurity"
      th/ akaqarsia/ (a) "impurity" - uncleanness. This is a state of sinfulness, sometimes referring to degenerate sexual sinfulness, although not here. This state of sinfulness/uncleaness produces "ever-increasing wickedness."
      th/ anomia/ eiV thn onomian "ever-increasing wickedness" - to lawlessness to/for lawlessness. Doubled = lawlessness on top of lawlessness. The preposition may indicate result (with a view to), "wickedness for wicked purposes", TEV.
      eiV aJgiasmon (oV) "leading to holiness" - to/for sanctification. Lit. offer/present your members as slaves to righteous toward/unto (the end/consequence of which is) sanctification. Again, the preposition is best taken to indicate result. The phrase parallels the idea of offering our members to impurity/sinfulness, the consequence of which is "ever increasing wickedness." Sanctification is the consequence of offering ourselves to righteousness. As noted above, "righteousness" here may refer to a state of righteousness in the presence of God, but more likely that righteousness, right-living, which is the natural consequence of a legal righteousness before God. One slavery leads to death, the other to sanctification. The NIV "holiness", or consecration is unclear. The final state, namely "holiness", may be in Paul's mind, or an orientation that reflects that (inaugurated/realized) state, "with a view to sanctification", CBSC.

v20
      eleuqeroi adj. "free" - "You were not under the influence of grace", or taken in a moral sense, "you were under no obligation to do what God required", TH.
      hn/ dikaiosunh/ (h) dat. "from the control of righteousness" - [you were free ones] to righteousness. The dative takes the sense either of "free with regard to", Moule, or "free from." Either, "not under the influence of right standing / righteousness before God", or the moral sense, "you were free so far as doing right was concerned", Williams.

v21
      tina oun karpon eicete tote "what benefit did you reap ......?" - therefore, what fruit had you then? The shorter question is to be preferred, "and what gain did that bring you? Things that now make you ashamed, for their end is death", REB, cf. NAB, JB.

v22
      nuni de "but now" - The present is now contrasted with the past.
      eleuqerwqenteV (eleuqerow) aor. pas. part. "have been set free" - having been freed. Aorist indicating a decisive act. Set free from the state of sinfulness (the unregenerate state) although justification also frees a believer to live (imperfectly) a righteous life, ie. "it leads to sanctification" ("holiness"?). The ultimate consequence is "eternal life."
      doulwqenteV de tw/ qew/ "have become slaves to God" - having been enslaved to God. Illustrating Christian commitment, "bound to the service of God", REB; "employed by God", Phillips.
      eiV aJgiasmon (oV) "leads to holiness" - [you have the fruit of you] to sanctification. It is possible that the fruit itself is "sanctification", "the advantage you get is sanctification", NRSV; although "the fruit of being made righteous" is possibly better, Phillips. On the other hand, the preposition "to/for", indicating purpose or result = "leads to", "yields a harvest", Moo, implies that "the fruit begins the process of sanctification (becoming holy)", Morris, the consummation of which is "eternal life." Note Morris' term "process". Sanctification is commonly defined as "the progressive realization of the person we are in Christ." Yet, the word "progressive" can lead to error, particularly where obedience to the law is used as a mechanism to "progress" Christ-likeness, holiness. We are best to view sanctification as a product of justification, a state of holiness, which, in the renewing power of the indwelling Spirit of Christ, we seek to realize in our daily life; albeit, always imperfectly. That is, we are holy, but also we strive to be holy (indicative / imperative again!).