There have been a number of comments on my previous post, concerning the nature of Romans 7. I realise that that I will be disagreeing with many learned people, and so I do not want to present a "final answer" to debate on Romans 7 - rather I just want to share some quotes from good commentators.
"Whatever else, this passage does not describe a struggle within the believer between his or her flesh and the Spirit but rather describes what it is like to be under the Law and in the clutches of sin and the flesh... The absence of the Spirit in this picture affirms that Paul is not describing life under the New Covenant." (Gorden Fee, God's Empowering Presence, p513)
"I do not then deny that Christians struggle with sin - I deny only that this passage describes that struggle. For while the believer continues to be influenced by both 'realms', Paul makes it clear he belongs to the new realm." (Douglas Moo, Romans, p449)
"My own view is that Paul's purpose in the text is not to delineate whether believers or unbelievers are the subject of the discussion. His purpose is to communicate the inability of the law to transform human beings." (Thomas Schreiner, Romans, quoted in Terry Virgo, God's Lavish Grace, p56)
"The argument supporting a reference to Christian experience is exegetical but existential... I agree with those who detect a future deliverance from sin in 7:24 but this should not exclude present victory as well. Believers experience substantial, significant and observable victory over sin." (Thomas Schreiner, Romans, p384)
"I am about to make a statement which is almost certainly to be misunderstood. I make it in order to expand the passage. I shall be 'slanderously reported' for having said it even as the Apostle himself was. I put it like this: it doesn't matter how deeply, how violently you may sin as a believer, you should never again come under condemnation. If you do it is because you have not understood your relationship to the law and have put yourself back 'under law' again... I say again that however much you may sin and whatever the charactter of the sin you must never put yourself back 'under the law': you must never have that sense of condemnation again." (Lloyd-Jones, Romans 7, p10)