Hi Paidion,
The Exegetical Insight in my version is different. It is by Paul Jackson.
The section is several paragraphs. Jackson's relevant comment on the grammar is:
The perfect passive participle σεσῳσμένοι is used in tandem with ἐστε to form what is called a "periphrastic verb", a construction intended to place special emphasis on the continuing results. Paul is using this construction to emphasize that the effects of salvation are an ongoing part of a believer's life.
He then goes on to give his analysis of the verse based on the "lifeboat analogy": salvation is a process with a beginning, middle and end; in a storm you get on a lifeboat (justification), the lifeboat makes its way to shore (sanctification), and you finally arrive (glorification).
Later in the chapter (p. 283 in my version) Mounce says:
Originally a periphrastic construction was used to emphasize the continuous force of the participle . . . however, by the time of Koine Greek, this emphasis is often lost. . . . Translate the periphrasitc construction just as you would the regular formation of the tense; perhaps the continuous idea will be emphasized, but that is up to the context and not the verbal form (see Exegetical Insight).
So there you have it. Mounce supports the "continuous idea", and thus you have:
For by grace you are being saved, through faith.
So, Παιδίον, you are in good company. Now, of course, you have to remember that Mounce says "perhaps", and "it is up to the context", so you have to look at that too.
Like I indicated before I agree with the progressive idea of salvation. And I really like what you have to say on the topic and your thought provoking questions. But we still have to deal with the context. Now, to me "the context" means Ephesians 2, and then the rest of Ephesians, and so on. It does not mean the "lifeboat analogy" that you [or Jackson] heard in church somewhere or in a seminary class. It does not mean my theological perspective, which would support progressive salvation. "The context" means, how can we tell what Paul is teaching us in Eph 2; and in order to do that we have to look at the whole chapter. And I just can't see anything there that indicates Paul is trying to explain a salvation process (instantaneous vs continuous). If not, as Mounce said, “Translate the periphrastic construction just as you would the regular formation” (which is, in fact, what just about every translation does: "have been saved" or "are saved" as in the KJV and a few others.)
I will also say (humbly, since I respect Dr. Mounce’s scholarship, and I will welcome correction), that I am quite dubious about the “continuous idea”, even as a “perhaps”. The perfect tense is just not translated “is being saved” or “are being saved”; it refers to a present condition based on a past action (e.g. “are in the condition of being saved”). Mounce seems a bit confused when he says (as quoted above):
Originally a periphrastic construction was used to emphasize the continuous force of the participle. . . however, by the time of Koine Greek, this emphasis is often lost.
You find a similar quote from Wallace (see
http://bible.org/article/participle#P858_81033), which is more carfully worded:
in classical Greek [a periphrastic] construction was used to highlight aspectual force. By the Hellenistic era, and particularly in the NT, such emphasis is often, if not usually, lost
Note that Wallaces uses the more precise "aspectual force" instead of "continuous force".
The “aspectual force” of a perfect means “continuing in its effects”; it does not mean “continuous in action”. So by “continuous force” Mounce meant (or should have meant) “continuing in its effects”. Thus if Paul was using the periphrastic (ἐστε - are) for emphasis it would only refer to their saved condition; it could not refer to the salvation process. If you look at the first quote from Jackson above you can see that he is also just refeferring to condition, not process.
But no matter how you come down on all this the really important question (as I see it) is: What is Paul trying to teach us in Ephesians 2? Just figuring out one verse by itself seems to be of limited value.