I'll give you a shorter answer, and then an extended one that takes a broader view of 2 Nephi 25:23 -- in light of LDS sources -- than what you've assigned it.
SHORTER ANSWER
The essential problem stated: 2 Nephi 25:23 combines a Johnny-come-lately God (His after-burner graciousness) and man (all he can do) as a supposed formula for salvation.
Now what other verses within LDS official "Scripture" combine these same components?
(a) Doctrine & Covenants 90:23 mentions receiving "grace upon grace" according to commandment-keeping (I cite this passage in full later in the post).
(b) D&C 130:21 is parallel to "grace" when it mentions us "obtain[ing] any blessing from God" and is parallel to "all we can do" when it stresses obedience:
And when we obtain ANY blessing from God, it is by obedience to that law upon which it is predicated. (D&C 130:21)
So, according to Mormon "Scripture" within the umbrella of doctrine & covenants, who triggers God's grace -- God's own lovingkindness, or man's obedience? Well, D&C 130:21 says God's blessings is ONLY "predicated" upon man's obedience.
So, in this context, what is "all you can do"? -- it's 100% obedience to the law. (Have you accomplished this?) I mean according to this verse, yes, you may receive God's blessings as you obey, but that still doesn't address the "ALL" part of 2 Nephi 25:23.
So, I dare you. Make a list of EVERY ordinance and EVERY commandment that LDS leaders have said through the years that are necessary for eternal progression/celestial kingdom.
Also, as far as the saved by grace argument...
OK, my "longer answer" below addresses your previous appeal that I use LDS sources + addresses this question: "Why 'saved by grace' a mere 'argument' to you?"
Doesn't 2 Nephi 25:23 mention the absolute necessity of God's grace?
Doesn't D&C 90:23 mention the absolute necessity of receiving God's "grace upon grace?"
Doesn't D&C 130:21 mention the absolute necessity of being "blessed" by God?
So, I ask you: "Are you not convinced that you NEED God's grace?" "And, how are you then going to trigger it? -- and do you have 'enough' to trigger it?"
LONGER RESPONSE
Please note your progression -- something you're obviously forced to do based upon the steep demands of 2 Nephi 25:23. What you've done is to take a concept that focuses on God -- His graciousness -- and looked purely at man -- and have essentially concluded that "good works" is the measure of his relationship with God. (Am I right?)
(Note this tendency: when Mormons get into a convo about salvation -- which is supposedly what the heart of 2 Nephi 25:23 is about -- they NEVER-to-RARELY zero in on God's grace...man is the measure and this relationship is operational on a tit-for-tat basis!)
My question is, "Why is it that when 'salvation' is mentioned, almost Pavlov-like, the convo immediately turns to 'good works?'" Where is your discussion (if ever) of God's grace?
So, let me turn around the challenge: What do LDS sources say about "grace?"
(1) 1979 "The Holy Bible: With Explanatory Notes and Cross References to the Standard Works of the Church of Jesus Christ of Latter-day Saints" Now why do I start off with this? Because when you look at the "Topical Guide" in the back, and look for an entry under "Grace" there is none. Oh sure, there's an entry under "Grace, Man May Fall from" -- but that entry focuses on what man does (or fails to do) -- not upon God. Right after that entry is one for "Gracious" -- citing several verses about God being "gracious"...but only three verses about God's grace applied to men. (Keep in mind, that the LDS "Topical Guide" entries for "Highway," and "Hissing" and "Manner" and dozens of other words in this guide are longer than this "gracious" entry -- showing that grace ALWAYS gets short shrift in the Mormon church!)
(2) Bruce R. McConkie, LDS apostle, wrote Mormon Doctrine. On pp. 338-339 of the 1966 edition, McConkie devotes just two graphs to "Grace of God". Once again, LDS leaders have trouble talking about "Grace" beyond God being gracious (trouble actually applying grace to man). Here's what he says at the start of graph 2: "Grace is granted to men proportionately as they conform to the standards of personal righteousness that are part of the gospel plan." (p. 339) (So McConkie keeps up exactly what I said in my earlier post -- to Mormon leaders, grace is earned and merited based upon personal righteousness. It's not as the Bible defines it -- a gift based upon God's own mercy...see Eph. 2:8-9)
(3) McConkie in this same paragraph goes on and cites Doctrine & Covenants 93:20: "If you keep my commandments you shall receive of his fulness, and be glorified in me as I am in the Father; therefore, I say unto you, you shall receive grace for grace." (Once again, to Mormons, "grace upon grace" is founded only upon commandment-keeping)
(4) And finally, let's look at Joseph Smith himself, in his book Teachings of the Prophet Joseph Smith. On the one hand, Smith says human perfection can ONLY be accomplished as we interact with angels: "Thus angels come down, combine together to gather their children, and gather them. We cannot be made perfect without them, nor they without us..." (p. 159)
But then later (May 1842), Smith is giving a message: "President Joseph Smith read the 14th chapter of Ezekiel...the people should each one stand for himself, and depend on no man or men in that state of corruption of the Jewish church that righteous persons could only deliver THEIR OWN SOULS--applied it to the present state of the Church of Jesus Christ of Latter-day Saints..." (pp. 237-238)
So who delivers the souls of Latter-day Saints?
Is it Jesus? (Nope)
Is it Joseph? (Nope)
Is it the brother who is baptized by proxy for you? (Nope)
Is it yourself? (Yup)
So, Smith said "perfection" comes ONLY based upon interaction with angels, said Joseph. (Why didn't anyone bother to ask, which side of the original angels?)
Also, as far as the saved by grace argument, how do you explain the “faith without works is dead” scriptures & the like?
A woman can get pregnant doin' nothin' but being receptive; but a mature baby comes only thru labor. A pre-born baby minus labor is a miscarried or aborted baby. But that doesn't mean that Mom is the ultimate source of new life. (The Creator is). That's why both the Bible AND the Book of Mormon describe our new life in Christ as being "born again" (book of Mosiah, for example).
...please explain how your interpretations are correct while in direct contradiction w/ other Christian religions who read the same Bible & believe in the same God.
I'm sorry, but I don't respond to terribly vague challenges -- "other Christian religions who read the same Bible" -- who/what are you referencing?
We believe all will be saved through that atonement (save the sons of perdition), however, not all will receive all that he has. Therein lies the rub. I noticed you didn't address the scriptures I cited re: works which contradict the grace only theory.
Your statement that “all we can do” is 100% obedience to the law, unfortunately shows your complete ignorance of our beliefs & doctrine on the matter. There is only One that has ever been perfect or ever will be during our mortal sojourn here on earth. “all that we can” in these tabernacles of clay is far short of 100%. Christ is the One that takes us the rest of the way through the atonement but not by us doing nothing, thus the scriptures re: works.
We are all saved via the atonement & His grace. But there is a difference between being saved, & inheriting all that he has for us. I think the problem you're having is understanding the difference between being saved & grace & what grace encompasses. You seem to cherry pick verses to make your argument but ignore those that contradict it (i.e. works)& that goes for the Bible as well as the BOM. It would seem you're more concerned w/ winning the argument than a reasoned discussion in search of truth. Your taking out of context the words of the prophets is also somewhat disconcerting. That's a shame.
Lastly, as far as the terribly vague challenges are concerned, perhaps I should have been clearer. My “challenge” could be for any number of doctrinal differences, but let's just start w/ the grace vs. works. Why is your version & understanding of grace only the correct interpretation & that of your Christian brethren that disagree wrong? Many Christian churches believe in Grace & works which is contrary to your assertions. Who's correct & why? Obviously this isn't the only difference, but let's start there. My best to you as always.