For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek. For in it the righteousness of God is revealed from faith for faith, as it is written, “The righteous shall live by faith.” (ESV)Paul says he will preach the Gospel without shame to everyone in the Roman and Jewish worlds because it is the power of God for salvation to them all: "To the Jew first, and also to the Greek." The word Greek is simply another way of saying non-Jew: To the Jew first, and also to the non-Jew. To everyone.
A Jew, a Greek, and a Barbarian Walk into a Bar . . .
I do not have a punchline for this, but it does sound like a great setup. On first reading, this sounds like an order of priority, but I rather think it is an order of historical sequence. If it were an order of priority, we could infer that the Jews get first crack at the Gospel because they have some sort of priority over everyone else. According to the order of priority theory, the Jew in that scenario is the first to whom Paul owes the Gospel as a matter of priority. They have been, after all, God's chosen people for millennia and still hold a special place in God's heart.
However, I do not believe Paul to be presenting an order of priority. Instead, I believe he is presenting an order of historical sequence. What is the difference between an order of priority and an order of historical sequence?
The historical sequence is a matter of then and now: first, during the Old Testament and mostly concerning the Jews, salvation was by faith. Second, in the New Testament and concerning Jews and gentiles, salvation is still by faith. There is no difference between the way of salvation then and now.
Paul makes this most clear in Romans 4 when he argues that Abraham was justified prior to his being circumcised, thus proving that Old Testament justification was by grace through faith and not by works: "Abraham believed God and it was counted to him as righteousness."
With this in mind, we can now explain that mysterious phrase in verse 17: ἐκ πίστεως εἰς πίστιν.
According to the ESV, the righteousness of God is revealed in the Gospel "from faith for faith," which I have already said is relatively meaningless in English. Stare at it all day and it still won't make any sense. The most straightforward and simplest way to translate the phrase is "from faith to faith."
If Paul has indeed presented an order of sequence, and if he is saying that salvation was the same for the Jews then as it is for the gentiles now (which he is), then "from faith to faith" simply means that the righteousness of God was revealed by faith then and it is revealed by faith now. So with this understanding we can paraphrase the two verses like this:
I am not ashamed of the Gospel through which God exercises his power to save everyone who believes. It does not matter whether you are Jew or gentile, salvation has always been by faith. It was by faith in the Old Testament; it is by faith in the New Testament. Nothing else saved them then. Nothing else will save you now. From faith then to faith now. All are saved the exact same way--through faith.
And then, to certify this assertion by giving it the mark of the authority of Scripture, Paul quotes an Old Testament passage (Habakkuk 2:4) that clearly teaches that righteousness came by faith then:
As it is written, “The righteous shall live by faith.”
My understanding of the phrase "from faith to faith" is very simple, matches the most straightforward translation of the Greek, and, as thematic foreshadowing, is reiterated throughout the book: It does not matter who you are--Roman or Jew, Greek or barbarian, wise or foolish--Salvation only ever came to man from God one way. Everyone is saved the same way--through faith in the Gospel. From faith then to faith now.
From faith to faith.