I'm convinced that the 6th is Mahler's most German and, simultaneously, most anti-German symphony. Hence, the need for bringing the march to the symphonic forefront. I think it's a mistake to view the 6th as a work that's primarily about Mahler's own personal problems. It's always said that Mahler wasn't interested in politics. I make the opposite argument: there were truly few composers who were more political than Mahler. It's just that Mahler was very guarded and cryptic when it came to discussing his own works, regardless of the fact that he was anxious to get them performed. But Mahler made perhaps THE most political statement of any composer ever: "I am thrice homeless; a Czech among Austrians; an Austrian amongst Germans, and a Jew amongst all peoples of the world; Never wanted, never welcomed". Of course, that's a typical Mahlerian exaggeration. But everything WAS an uphill struggle for Mahler. Nothing was handed to him, for the most part. If you use that statement as a launching platform, it's clear that the sixth symphony was very much a prophetic work, and thus, a warning. As I have pointed out many times, there was nothing unusual or rare about artistic warnings at that particular time in history, as many people viewed the first world war coming from a mile away (I mean that in the figurative sense). Barbara Tuchman discusses this to some length in "The Proud Tower".
If you accept my basic premise about the 6th symphony, then the true purpose of the 8th symphony becomes clear. The sixth pointed a finger at the basic problem of the German speaking world at that time. The 8th then points the way out of the tunnel of darkness. Just as Mahler's personal problems are a parable or allegory for the bigger issues that the sixth symphony is dealing with, so is Goethe's text only a parable or allegory for what Mahler is trying to say to his public with the 8th. Mahler himself left the biggest clue when he called his 8th his "hymn" or gift to the nation (I've read both words used). Being aware of his critics, he also told Alfred Roller, "there's my mass". Therefore, I would argue that Goethe's text is not terribly important at all, until we reach the final "Chorus Mysticus". In fact, the real point is the poetic level of Goethe's German. In that sense, it's like reading Shakespeare (only Shakespeare is even more cryptic, with his many political references). I think it's the musical issues that are more important, or more interesting.
In many ways, the 8th summarizes everything that had happened in western music up to that very moment. At the very least, that's certainly true for the Austro-German line of composers. In a way, the 8th is the Beethoven's 9th of the Belle Epoch, or Art Nouveau ear (sorry, I don't have time to fix spelling mistakes now). At the start of Part II, Mahler is "tone painting" in the classic way that Schubert or others would have. He's setting the scene for Goethe's text. But then the music shifts into Wagner-like episodes, beginning with the first loud outburst, and going all the way until the first entrance of the childrens chorus (right after the bass baritone solo). At the point Mahler switches to Mendelssohn, with strong overtones of his "Midsummer Night's Dream". At the very least, you could certainly argue that the text for the three penitent women is well worth ignoring, unless you take the whole issue of redemption quite seriously, or literally.
Mahler tried to express all this in a letter to wife his; one in which he became a bit tongue-tied. He tried to make it clear that the focus was on the "Chorus Mysticus", and what it was that Goethe was attempting to express with it. It's little wonder that "cosmic", psychodelic children of the '60s could relate so easily relate to Mahler. Goethe and Mahler are sort of making an acid trip of the soul. As with so many other "heaven storming" moments throughout his entire ouevre (again, please pardon the spelling mistake), Mahler reveals heaven as little more than sheer energy - a much more medieval idea of what heaven is about. It's simply too bright and powerful to observe or comprehend from Earth.
So what am I saying? . . . forget the text, once you've read the bloody thing. All that truly matters is the tone painting aspects of Part II, and then the final "Chorus Mysticus".
Poll