Would very much appreciate some feedback on this. I have tried to put all of it in my own words without referring to influential sources.
Clearly some of it needs more reasons (like the GR’s presence in every major culture/religion, how the GR resolves practical ethical dilemmas, the evidence for Jesus’ death/resurrection, biblical basis, et cetera), but the following is just a summary. If given the time and opportunity, I’d expand upon it. Any thoughts on the following?…
Every major culture/religion hungers for the answer to the question of Ethics, and only one of the answers, the Golden Rule, is found in every major culture/religion. The universal presence of that answer does not justify it, but the universal hunger for an answer does suggest there is something to satisfy that hunger. The question, or hunger, of Ethics can be phrased “How and why should we be or behave with the Other/self?” Coming late on the scene, all of the theories in Ethics besides the Golden Rule focus on only 1) how we should ‘be’ (character or virtue theories), 2) what we should ‘do’ (conduct or duty theories), or 3) the ‘end’ (consequentialist theories), and they run into difficulties when it comes to whether self or Other should take priority. In contrast, the Golden Rule answers the question by describing the ‘end’ of what we should ‘do’ and how we should ‘be’ (be=do=end) as treating the Other as self (self=Other), as not merely recognizing a sameness between self and Other, but acknowledging that sameness in our behavior with self/Other. So the Golden Rule is the only theory in Ethics which completely answers the question, the only one which has the most justification to be believed and lived.
But in order to be objectively real, it cannot be purely theoretical—it must also correspond to reality—there must be a real being whose nature and behavior (including commands) is described by the Golden Rule. Justification is about having good reasons to believe something is true, to believe that it corresponds to reality. However, just because we are justified in believing something is true does not necessarily mean it ‘is’ true, otherwise we would never know what it is like to be wrong. So the fact that the Golden Rule is the most justified theory in Ethics does not prove its correspondence to reality, for that would commit the reverse of Hume’s is-ought (the ought-is) fallacy. The Golden Rule is true only if it actually corresponds to real being, and regardless how good or bad our reasons.
On the flip-side of the same coin, the mere existence (or assumed existence) of this being cannot justify the Golden Rule, for that would commit the is-ought fallacy. Just because we believe something that is true (or is at least assumed to be true), does not mean we have good reasons for believing—we could be right by accident. Fortunately there are at least two good, strong reasons which justify believing the Golden Rule not only completely answers the question of Ethics, but also corresponds (is true) to real being: 1) as already mentioned, we have a universal hunger for the answer to the question of Ethics, and 2) there is evidence of the being which the answer describes, to which the answer corresponds.
First, universal physical hunger indicates that food existed long enough for us to evolve that hunger for it—likewise, universal spiritual hunger for true meaning (acknowledged even by the self-proclaimed Four Horsemen) suggests there is an actual being described by self=Other. Second, there is evidence, internal and external to the biblical record, of Jesus’ substitutionary sacrifice as the ultimate demonstration of Golden Rule love, and of his divine resurrection. So we are justified in believing in a being described by the Golden Rule because 1) it satisfies the hunger (answers the question) of Ethics, both 2) theoretically (be=do=end, self=Other) and 3) practically, by way of ultimate demonstration (for love is not love without demonstration) (aka revelation). If we are not wrong about any of those reasons and such a being actually exists, we don’t merely justifiably believe, we correspondently know, for knowledge (as Plato affirmed long ago) is belief that is both 1) justified (in that the evidence obligates us to believe something corresponds to reality, whether or not it does), and 2) true (in that something corresponds to reality whether or not we have good reasons to believe it does).
All of the above A) resolves Euthyphro’s (and another unnamed) dilemma between natural law and divine command/revelation [because 1) God commands/reveals in accordance with his good nature, and 2) we can know the Golden Rule through reason and intuition only if it corresponds in order to be known—the dilemma this resolves ought to have a name if it doesn’t already], B) affirms Hume’s is-ought distinction rather than defying or dismissing it (and without dissolving into skepticism), and C) dismantles Gettier’s problem while affirming its underlying intuition (more on that here http://ichthus77.blogspot.com/2011/01/answering-gettier.html), preserving Plato’s justified-true-belief definition of knowledge.
Discussed here on Facebook.
Also see: The Golden Rule (self=Other) and God
Ichthus77 
With 1)God commands/reveals in accordance with his good nature, isn't actually a proof for God's good nature. It's not even an induction. So it can't simply be assumed, let alone assumed to answer how God, being an independent mind, would or could define “good” or by what accordance of his own Will or Dictates he can or cannot abide.
So I still don't think it avoids the problem of subjectivity.
With 2) we can know the Golden Rule through reason and intuition only if it corresponds in order to be known, I think William James answers this in his work. The good may be of pragmatic value, but it doesn't require the good to be purposeful in and of itself. Sam Harris' 'Moral Landscape' expands upon this. But you could look at the work of Thomas Hobbes as well.
Basically, according to the goods which serve a practical good, these can be utilized in a way which help us achieve a greater good, but there may never be an ultimate good. There may only be general or generic versions, which we can only know by trial and error, so we come to recognize them, not by intuition, but by experience of the success of those which work and the failure of those which don't. Therefore certain things which once seemed like a moral good, might in fact, change to prove outdated by today's moral reasoning.
As for this 'universal hunger' you speak of, this could also be explained from a Naturalistic and Evolutionary worldview. So the burden would be on you to explain why your version which relates to the properties of God supersedes these other explanations for the same “universal hunger'.
Anyway, just some food for thought.
Tristan,
You say, “1) 'God commands/reveals in accordance with his good nature,' isn't actually a proof for God's good nature. It's not even an induction.”
Many arguments are made with certain givens. The Euthyphro dilemma's given is the Good. My argument is this: “If” the Good exists, or “granted” the Good exists, then God wills/commands according to it.
You say, “So it can't simply be assumed, let alone assumed to answer how God, being an independent mind, would or could define “good” or by what accordance of his own Will or Dictates he can or cannot abide. //So I still don't think it avoids the problem of subjectivity.”
You want it to answer how God, being an independent mind, would (or could) define the Good–or by what accordance (???) of his own Will or Dictates he can or cannot abide. This is worded so confusingly, but I think you mean that the resolution to the Euthyphro dilemma does not provide a definition of the Good. With that I agree–it only deals with ontology, not epistemology. See our discussion on that here, where I also answer the charge of subjectivity: http://www.ichthus77.blogspot.com/2012/10/dialogue-on-euthyphros-dilemma-with.html Note that my position is that God wills/commands in accordance with his nature–his commands do not define a new good–the definition of the Good never changes and corresponds to his nature. He cannot contradict his own nature–that would make him less than absolute/ultimate.
“With 2) we can know the Golden Rule through reason and intuition only if it corresponds in order to be known, I think William James answers this in his work. The good may be of pragmatic value, but it doesn't require the good to be purposeful in and of itself. Sam Harris' 'Moral Landscape' expands upon this. But you could look at the work of Thomas Hobbes as well.”
I answer pragmatism, utilitarianism and Sam Harris elsewhere on this blog and my Sword and Sacrifice blog. Referring to people instead of arguments is not helpful to our dialogue… Can you answer this: If there is moral truth, to what does it correspond?
You say, “…but there may never be an ultimate good.” Do you mean may in the sense of…”there is absolutely no possible way there could ever be an ultimate good”? Or do you mean it in the sense of “…it's possible we may never discover an ultimate good”? (because it wouldn't make sense to say that one may just pop into existence). Socrates, and anyone interested in getting at moral truth, is not concerned with the sort of “good” you are putting forth.
You say, “As for this 'universal hunger' you speak of, this could also be explained from a Naturalistic and Evolutionary worldview. So the burden would be on you to explain why your version which relates to the properties of God supersedes these other explanations for the same “universal hunger'.”
My version doesn't supersede the other explanations: I believe the universal hunger was evolved (whether or not it was with God's assistance, I am still researching), just like our hunger for food. Just as there must have been food enough for us to evolve a hunger for it: There must be “real” meaning in order for us to evolve a hunger for it.
Sorry it took me so long to reply! Thanks for this discussion :)
I bring this discussion to the top of my blog here: http://ichthus77.blogspot.com/2012/10/dialogue-with-tristan-on-golden-rule.html#more