Paul’s Mysterious Man in Romans 7:14-25

I really enjoy detective stories and shows. Whether it’s Sherlock Holmes, Frank and Joe Hardy, or even Sheriff Hopper, there really are stranger things that need solving. One of these stranger things is Paul’s mysterious man in Romans 7:14-25. This perplexing passage has divided even the best biblical scholars and theologians. The great church father and theologian Augustine even changed his mind on this passage, which is really saying something, since most theologians and Bible scholars never admit when they’re wrong. So what’s going on in this passage?
Romans 7:14-25 describes a person in turmoil: “I am all too human, a slave to sin. . .nothing good lives in me, that is, my sinful nature. I want to do what is right, but I can’t. I want to do what is good, but I don’t. I don’t want to do what is wrong, but I do it anyway. . .Oh, what a miserable person I am! Who will free me from this life that is dominated by sin and death?” (Romans 7:14b, 18-19, 24 NLT). You could read the entire passage if you have time for a greater sense as to what is happening.
There are basically four or five theories as to the identity and experience of Paul’s mysterious man.
Theory #1: Paul is referring to himself, demonstrating a normal, (even mature) Christian experience. This was the interpretation of the Reformers (Luther, Calvin), John Owen, and those who follow in their footsteps today like J.I. Packer, R.C. Sproul, John Piper. This was also Augustine’s second position. The strongest argument for this view is probably verse 22: “For I delight in the law of God, in my inner being (ESV).
Theory #2: Paul describes the experience of an immature Christian believer. This view points out the absence of the Holy Spirit in Romans 7:14-25, saying the believer needs to move from Romans 7 to Romans 8 as she learns the benefits of being in Christ. This view is not necessarily held in scholarship but is on a popular-level.
Theory #3: Paul describes the experience of every non-Christian person.
Theory #4: Paul describes his own experience as a non-Christian but as a devoted Jewish believer. Theories #3 and #4 were held in various forms by most of the early church fathers, Augustine (1st view), and by contemporary New Testament scholars like Gordon Fee, Douglas Moo, and Preston Sprinkle.
Theory #5: Paul isn’t necessarily describing a Christian or a non-Christian, but rather shows how the law and morality living is unable to transform us (Thomas Schreiner, Martyn Llyod-Jones, F.F. Bruce).
I personally find theory #4 the most compelling, that Paul is referring to himself as a Jewish believer before he met the risen Jesus. I used to hold to theory #1, that Paul is referring to himself as a Christian. The problem with this view is in the strong language of slavery, defeat, and death used. Is a Christian “sold under sin?” Is a Christian powerless to do good? Does a Christian live in a body of death? Romans 7 doesn’t seem to describe someone just struggling with sin but rather someone who is enslaved by sin. The contrast with the victorious life of Romans 8 couldn’t be stronger. The delight that Paul has for God’s law (7:22) means that he’s not just any non-believer (theory #3), but that he’s a Jewish believer who hasn’t met Jesus yet, until verse 25: “Thank God through Jesus Christ our Lord” (for his rescue).
I’m not married to this idea, and could also change my mind like Augustine. What do you think? Who is Paul referring to in this complex passage?