So Paul was a Jew, a descendant of Abraham. He tells us he was from the tribe of Benjamin and a "Hebrew of the Hebrews" (Phil. 3:5). By this expression he meant to say not only that Aramaic was a first language for him, but that he was raised on the values of "purist" Jerusalem society. These were the ones who thought they did Judaism the right way, not like those "Diaspora," scattered Jews. They spoke Greek at best and at worst spoke whatever obscure local language was the native tongue where they lived. 
In Philippians 3:5, he goes on to say that he had a Pharisaic approach to the Jewish Law before he believed.  Indeed, he says in 3:6 that he was faultless when it came to the kind of righteousness you could have in relation to the Jewish Law. This is a statement we are generally programmed to skip over. What? Paul says he was blameless in some way in relation to his Law-keeping before he believed on Christ? Never noticed that before!
If we can get beyond the kinds of things people say so often about Paul and actually listen to what he has to say, we will soon be struck by a number of things. If we let him construct his sense of himself, both before and after he believed, we will not likely conclude that he was the kind of guy who likely felt like a moral failure before he turned to Christ. Nor did he think of himself as a slave to sin after he followed Jesus. 
For example, in Philippians 3, as in 2 Corinthians 11, Paul does not discuss his past as a time of failure. Instead, he says that "whatever were gains to me I now consider loss for the sake of Christ" (3:7, TNIV). He calls his Jewish badges of honor matters of potential "gain," not illustrations of his past sinfulness or moral failure.
So a little bit later on, when he says, "forgetting what is behind," he is not forgetting all his past failures. He has said nothing of the sort. He is forgetting things that, from a certain human perspective, might have been quite impressive indeed! The problem is that these things did not make him righteous enough to demand God's favor. And besides, they paled next to the power of Christ's faithful death and resurrection.
Romans 7:14-25 is often taken as an obvious indication not only of Paul's past moral struggle, but indeed of the struggle he continued to have with sin as a Christian. Does not Paul use the present tense when he says, "the evil I do not want to do--this I keep on doing" (7:19)? And after all, don't so many of us Christians identify with Paul's alleged struggle with sin? Do we not find ourselves often struggle to do the right thing, even though on some level we truly want to?
But our identification with these words applied to our own lives does not change what Paul meant two thousand years ago. And the broader context of Romans 7 demands we not take these words of Paul's current struggle. In the chapter before (e.g., Rom. 6:17-18), the chapter itself (e.g., Rom. 7:5-6), and in the chapter after (e.g., Rom. 8:1-4) Paul urges that Christians are no longer slaves to sin but are now slaves to righteousness.
The majority of Pauline scholars thus now acknowledge that Paul is giving a dramatic portrayal in Romans 7:14-25 of those who want to do the good of the Jewish Law but are unable because they do not have the Holy Spirit to empower them. It is irrelevant that he is speaking in the present tense, since you would expect a person to use the present tense when playing out a hypothetical. In short, you would have to rip this chapter from its context to make of it what so many Christian readers today do.
Some scholars have acknowledged that Paul is not talking about his present in these verses, but suggested he is remembering the struggle of his past. All we can say is that Paul almost never gives off that sort of message when he talks about his past. We find nothing of this tone in Philippians 3 or 2 Corinthians 11. Words like "repentance" and "forgiveness" do not show up much at all in Paul's writings, as some fossil of former worries. At the same time, from his earliest letters he urges his churches to be blameless in their lives (e.g., 1 Thess. 5:23; Phil. 1:10-11) and is completely comfortable to suggest they follow his example (e.g., 1 Thess. 1:6-7; Phil. 3:17). 
No, if we want a picture of what Paul was like before he believed on Christ, we would more profitably read the Parable of the Pharisee and the Tax Collector in Luke 18:9-14. It is not hard to hear the same Paul who exerted such strong authority over his churches saying in his former life, "God, I thank you that I am not like other people--robbers, evildoers, adulterers"--and these lawless Christians. Is not his, "Hebrew of the Hebrews; in regard to the law, a Pharisee; ... as for righteousness based on law, faultless" similar to the Pharisee in Luke who says, "I fast twice a week and give a tenth of all I get" (Luke 18:12).
At the same time, we must be very careful not to make blanket assumptions about Judaism or even about Pharisees in Jesus' day. The caricatures that work so well in popular preaching have also fed holocausts and crusades from time to time in history. We are so used today to Christianity and Judaism being separate religions that it is easy to forget that the earliest Christians were Jews and almost certainly would have continued to identify themselves as Jews to their deaths. Paul speaks of Gentile believers being "grafted into" the tree whose "natural branches remained ethnic Jews (Rom. 11:17-21). And he believes that around the time of Christ's return, the bulk of non-believing Israel will believe (Rom. 11:26).
There is a popular fiction you sometimes hear out there in preaching, that Saul was Paul's Jewish name and Paul his Christian name. But the most superficial glance at Acts dispels this idea. The book of Acts continues to call him Saul some fifteen years into his life as a Christian, only suddenly to switch to Paul while Paul is on the island of Cyprus (Acts 13:9). The best answer to the question of Paul's dual names is that one of these is his nickname, and the other part of his name as a Roman citizen.
[to be continued next Friday..., d.v.]
 All the while we remember that Paul was from Tarsus in the Diaspora, that he was fluent in Greek, and, indeed, that as often as not he quotes Scripture from the Greek translation even when it differs somewhat from the Hebrew.
 In Acts 23:6, Paul identifies himself to the Jewish ruling council, the Sandhedrin as a Pharisee in the present tense, almost thirty years after he believed in Jesus. It was acceptable for historians of the day to compose such speeches (e.g., Thucydides tells his readers as much in Pelopponesian War 1.22), so we cannot be completely sure that Paul said exactly these words. Even if he did, he was surely saying it for rhetorical effect. The position Paul takes in writings like Galatians and Romans is light years away from anything a normal Pharisee would say.
 In the first chapter, n.1, I mentioned that I will be mentioning the fifty or so works on Paul that a person might read to master his writings. Here we should mention one of the most important of all, in my opinion. Other than reading Paul's writings themselves, you would do well to start the quest to master Paul with the late Krister Stendahl's, "Paul and the Introspective Conscience of the West," conveniently reprinted in his book, Paul among Jews and Gentiles (Minneapolis: Fortress, 1976), 78-96.
 The only real candidate for this argument is 1 Timothy 1:16, which calls Paul the "worst of sinners" before he believed. But as we will see in the companion volume to this book, 1 Timothy differs so significantly from Paul's earlier letters that one should not use it as the starting place or the "base camp" for understanding any aspect of Paul or his writings. And, in any case, calling oneself the worst at some point in the past, can actually serve as a badge of honor in the present, as anyone who grew up listening to conversion testimonies knows.