The last bread crumb on this trail was posted as "The Bottom Line." I am not happy with it, but I'll get discouraged if I don't move on. I vent a little in the notes below. I'll take it out before publication but it is an expression of my frustration at those who practice theological interpretation while pretending to do historical-cultural interpretation.
The Righteousness of God
The key verses of Romans are 1:16-17: "I am not ashamed of the gospel, for it is the power of God leading to salvation for all who have faith, both to Jew first and to Greek, for the righteousness of God is being revealed in it, starting with faith and ending with faith, just as it is written, 'But the one who is righteous on the basis of faith will live.'" This highly compact statement of Paul encapsulates the key ideas Paul is about to argue in the first four chapters of Romans. It sets down key words and phrases, like "gospel," "salvation," "faith," and the "righteousness of God."
The gospel for Paul is the "good news." He starts off the letter by mentioning that God set him apart as an apostle commissioned to spread this good news (1:1-2). What is the good news? It is the good news "concerning God's Son" (1:3). The good news is that God has enthroned Jesus as the Messiah, the promised king. God has appointed him "Son of God in power" by raising Jesus from the dead (1:4). And part of the good news is all that goes along with Jesus ruling--including salvation! 
In Paul's understanding, Son of God meant that Jesus was God's appointed king of the universe.  For Paul, when God raised Jesus from the dead and seated him down at his right hand in the highest heaven (e.g., Acts 13:33), God was enthroning him as "Son of God in power" on the throne of the universe. "Son of God" is kingship language, meaning that God has delegated to Jesus the task of judging and ruling the nations.
Salvation is about being saved in the coming judgment of God. The idea of being saved involves being saved from something. We often say we are saved from our sins, but this expression is a shorthand for being saved from the consequences of our sins. After all, it is not like our sins are following us trying to get us. No, when Paul and other New Testament authors talk about salvation, they are primarily referring to escaping God's wrath on judgment day, also called the Day of the Lord. 
The word faith (pistis) and its verb form, "believe" (pisteuo), wander between a sense of trust to a sense of faithfulness and of course to a sense of belief. While these English translations are all different (trust, faithfulness, belief), they are all nuances of the same Greek word. When Paul talks about the "faith of God" (Rom. 3:3), he obviously means the faithfulness of God. When Paul talks about our faith, he can mean things like our belief that God raised Jesus from the dead (e.g., Rom. 4:24) or he can mean our full commitment to and trust in the fact that Jesus is our Lord (e.g., Rom. 10:9). In the next section of this chapter, we will talk about whether Paul also mentions on a few occasions the faithfulness of Jesus Christ.
But this section is about the righteousness of God...
 N. T. Wright does an excellent job of focusing the good news of the gospel on the fact that Jesus is king (e.g., What Saint Paul Really Said, ***). But he is also quite dogmatic and rigid that this good news is not salvation. One gets the feeling that something more is going on in his mind than just what Paul meant by the word gospel. With Wright, one sometimes gets the feeling that his Reformed Anglican theology is secretly hiding below the surface, steering some of his more emphatic and idiosyncratic points. He looks to be doing historical-cultural interpretation before your eyes, but the direction of his pen is often directed as much by his covert theological impulses.
 If we are to get into Paul's head on these sorts of things, we have to forget for a minute some of what we know as Christians from God's continued revelation these last two thousand years. On the one hand, it would be foolish for us to reinvent the wheel. God helped the Christians of the first five centuries to unpack and unfold the significance of Jesus, asking questions that went way beyond anything on the minds of the first Christians. How exactly does Jesus' humanity and his divinity fit together, for example? The answers to which God led Christianity are the common Christian understandings of the Trinity and the dual nature of Christ. It would be silly--not to mention dangerous--to try to rehash these questions all over again.
But the legitimacy, probably even primacy of these Christian readings do not change the fact that what was going on in Paul's head when he wrote words like "appointed Son of God in power" had their first meaning in what words meant in Paul's day. For example, at the time of Paul, "Son of God" was an expressoin that could be used of any of the kings of the Old Testament and language of "bowing the knee" (worship) was appropriate to them. The royal verses Paul and other New Testament authors apply to Jesus were applied to Old Testament, human kings as well.
So 2 Samuel 7:14 was originally about Solomon and implied that he was God's representative, a human representative of God's authority on the throne of Israel. When Hebrews 1:5 quoted this verse, its author may not have been thinking quite as much about Jesus' divinity as we do when we read it. We know Jesus is fully God, begotten of God the Father from eternity past. But it is not at all clear that God had led the New Testament authors to figure quite this much out at that time. Christians came to these understandings through the continued direction of the Holy Spirit as they reflected further on the words of Scripture.
It is thus with mixed feelings that we read studies like Richard Bauckham's Jesus and the God of Israel. Bauckham's studies are a strange mixture of good theological readings of New Testament texts like Hebrews 1 and yet he cannot seem to free himself from the impulse to find these meanings by way of classical historical-cultural interpretive method. The result is brilliant and ingenious interpretation that, again, may very well be more steered by Bauckham's theological tendencies than by his surface level interpretation.
 Ephesians 2:8, which says, "we have been saved," is quite unusual for Paul's writings. As we will see later in this book, Ephesians is not typical of Paul's writings in the varied imagery it uses. For this reason, John McRay's Paul: His Life and Teaching is well-intentioned but probably misguided to use Ephesians as the launching point for summarizing Paul's theology.