Who is the wretched man of Romans 7?

Is the wretched man passage of Romans 7 describing a believer’s battle with sin or an unbeliever trying, but failing to keep the Law of Moses?  Should believers look to the Law of Moses for sanctification?  I think not and if we follow the immediate context of Paul’s letter to the Romans, he clearly distinguishes between law/sin and Spirit/grace.   

Romans 6:14 For sin shall no longer be your master, because you are not under the law, but under grace.
Under grace sin is not a believer’s master.  Therefore, why would believers want to place themselves under the law?

Romans 6:17-18 But thanks be to God that, though you used to be slaves to sin, you have come to obey from your heart the pattern of teaching that has now claimed your allegiance.  You have been set free from sin and have become slaves to righteousness.
Unbelievers are slaves to sin.  Believers have been set free from sin and are slaves of righteousness.  The wretched man is a prisoner of sin [Rom. 7:23].  How can a believer be set free from sin and yet remain a prisoner of sin? 

Romans 6:20-22 When you were slaves to sin, you were free from the control of righteousness.  What benefit did you reap at that time from the things you are now ashamed of? Those things result in death!  But now that you have been set free from sin and have become slaves of God, the benefit you reap leads to holiness, and the result is eternal life.
Believers were slaves to sin but have been set free from sin… IOW, no longer have to sin.  Believers are now slaves of God.  How can a believer be set free from sin and still be a prisoner of sin [Rom. 7:23] at the same time? 

Romans 7:4-6 So, my brothers and sisters, you also died to the law through the body of Christ, that you might belong to another, to him who was raised from the dead, in order that we might bear fruit for God. For when we were in the realm of the flesh, the sinful passions aroused by the law were at work in us, so that we bore fruit for death. But now, by dying to what once bound us, we have been released from the law so that we serve in the new way of the Spirit, and not in the old way of the written code.
Unbelievers are in the flesh and in sin that bears fruit for death.  But now believers have died to the law and bear fruit for God.  Believers serve God in the new way of the Spirit and not in the old way of the written code.  Why would a post conversion Paul immediately go from saying this to talking about serving in the old way of the written code and failing?  It makes no sense.     

Note that in the past three passages Paul makes a clear distinction between believers and unbelievers, law and grace, Spirit and flesh, Spirit and written code…  

Romans 7:14-16 We know that the law is spiritual; but I am unspiritual, sold as a slave to sin.  I do not understand what I do. For what I want to do I do not do, but what I hate I do.  And if I do what I do not want to do, I agree that the law is good.
The man here is a slave to sin.  He is unable to do follow the law although he admits the law is good.  Does this sound like the believer Paul has described in chapter 6 and chapter 7 verse 6 that has been set free from sin and serves in the new way of the Spirit?  No, this is a pre-conversion Paul that is serving in the old way of the written code and has not yet become a believer.

Romans 7:19-20 For I do not do the good I want to do, but the evil I do not want to do—this I keep on doing.  Now if I do what I do not want to do, it is no longer I who do it, but it is sin living in me that does it.
Does this really sound like a person who has been set free from sin, serves in the new way of the Spirit, and is a slave to righteousness?  No, this person is trying to serve in the old way of the written code… he is not yet resting in the blood of Christ.

Romans 7:24-25 What a wretched man I am! Who will rescue me from this body that is subject to death?  Thanks be to God, who delivers me through Jesus Christ our Lord!
Hmmm! Are we to believe the man who was rescued from sin in chapter 6 and became a believer is now once again a slave to sin and needs more rescuing!!!  No I think not, I believe the wretched man is an unbeliever attempting to keep the law of Moses and he realizes that it is Jesus Christ who delivers him from the curse of the Law.  He is finally looking to Christ instead of the abrogated law of Moses. 

Romans 8:1-2 Therefore, there is now no condemnation for those who are in Christ Jesus,  because through Christ Jesus the law of the Spirit who gives life has set you free from the law of sin and death.
Paul starts all over describing how the law of the Spirit sets an unbeliever free from the law of sin and death.  If this had already happened to the wretched man, why would he need it to happen again?  Does a believer oscillate between being wretched and being free from the law of sin and death?

CONCLUSION:  Why would Paul totally divorce law keeping from the gospel of grace in Romans 6, the first part of Romans 7 and then reverse course in the wretched man passage by presenting law keeping as normal in a believers life?  Was he schizophrenic?  The whole epistle to the Galatians was written to refute keeping the Law Moses for justification or sanctification.  The Jerusalem Council ruled against it [Acts 15].  Look at following passages:
Galatians 3:1-3 You foolish Galatians! Who has bewitched you? Before your very eyes Jesus Christ was clearly portrayed as crucified.  I would like to learn just one thing from you: Did you receive the Spirit by the works of the law, or by believing what you heard?  Are you so foolish? After beginning by means of the Spirit, are you now trying to finish by means of the flesh?

Also:
Galatians 5:18 But if you are led by the Spirit, you are not under the law.

Clearly Paul does not recommend, “finishing” through law keeping by means of the flesh.  Therefore why would a believing Paul be finishing by the law in the wretched man passage?  

Note: I fully affirm that believers should seek to live Godly and Biblical ethical lives through the indwelling Spirit [Rom 8:12-14, Rom. 7:6] and the law written on the heart.  I also affirm the reality of indwelling sin in the lives of believers.  However, Romans 7 is not about indwelling sin… It is about the error futility of trying to keep the Law of Moses, which has been abrogated [Heb. 8:13, 2 Cor. 3:7-9].  Note Paul’s point in the following passage where the ministry of death clearly refers to the Ten Commandments:
2 Cor. 3:7-9 Now if the ministry that brought death, which was engraved in letters on stone, came with glory, so that the Israelites could not look steadily at the face of Moses because of its glory, transitory though it was, will not the ministry of the Spirit be even more glorious? If the ministry that brought condemnation was glorious, how much more glorious is the ministry that brings righteousness!

Are we to believe that Paul as a mature believer in Romans 7 is trying to keep the Ten Commandments that he calls a ministry of death?