Just as a side note on Biblical symbolism and also allegory.
You know the reference to the "system of things" sometimes mentioned? The "system of things" is a reference to the current order or things or the way things are, the current situation dictating at the time. Well the order of things is reflected most pertinently in the order of the heavens, the predictable and consistent order of things in heaven and the rotation of the earth, it's consistency, etc. Therefore another parallel reference to the "system of things" is sometimes calls "heaven and earth."
Thus in one place where Christ mentions the "end of the system of things" and in other place "heaven and earth might pass away", he's talking about the same thing. So especially when the Bible speaks of "heaven and earth" passing away, it is not speaking of the literal heaven and earth, obviously, but the current system of things.
This is a way the Bible changes venue, if you will, from one set of circumstances to the other. It is very helpful as well to keep things in chronological order, since when it it mentioned that heaven and earth fled or passes away, it is talking about the current system of things ending, and a new order or situation now being established. Thus we find the reference at Revelation 20:11 speaking of "the earth and the heven fled away, and no place was found for them." This is at the critical juncture of a great change in the "system of things" or the current situation. This is when the world goes from when Satan is released testing mankind to when Judgment Day begins. Satan's final testing of mankind was one venue in process at that time, but when that is over and he is destroyed, a whole new venue comes in, Judgment Day and the judging of all mankind. There is no Satan. Thus that system of things, that "heaven and earth" are said to be no more and to have passed away.
Likewise, we find a similar expression when the specific circumstances of Judgment Day is ended. After all the wicked are killed and all the righteous get eternal life, the judging is over. Thus another period or system of things passes away and a new system of things then takes over. Thus at Revelation 21:1 it says, "And I saw a new heaven and a new earth, for the former heaven and the former earth had passed away." This simply means one system of things is being replaced by another. One heaven and earth is being replaced by another heaven and earth, or order of things. In this case the rules and focus of Judgment Day are no more and have passed away, and the next phase of what is to happen next, a new order of things is now in place.
Understanding that "heaven and earth" is equivalent to the current "system of things" is quite helpful in preventing us from introducing events out of chronological order. Case in point once Judgment Day begins and it mentions that earth and heaven are no more and have passed away, we know that everything that happens during Judgment Day, including the second resurrection has to occur after Satan is destroyed in the lake of fire, because Satan was part of that old system of things, that old "heaven and earth" that have fled and are no more. Thus in particular, JWs generally think that the resurrection, though clearly described after Satan is destroyed, actually happens during the millennium, but it doesn't. By noting that the old heavens and earth had fled it keeps this part of the text in strict chronological order.
It is quite complex, all the allegory combined with trying to understand local colloquialisms, but once one looks closely enough with an effort to actually understand what the writer is trying to say, instead of trying to read our own agenda into the text, then these wonderful little nuances make themselves apparent and the references are understood in their true context.
Just as a note, therefore, when Jesus talked about the "end of the system of things" that would not occur until the "good news" was preached worldwide, he was not talking about the end of the world, or the end of the system of things that ends with Armageddon. Instead he was speaking of the system of things currently in place for the Jews, the system of things of the "gentile times" or the "appointed times of the nations." That system of things ended in 1947 when the Jews finally came out of exile and had a country of their own again, as promised would be granted on the heels of the "great tribulation", a tribulation like the world had never seen nor would see again. That was the Holocaust. So when Jesus said at Matthew 24:34 "Truly I say to you that this generation will by no means pass away until all these things occur. Heaven and earth will pass away, but my words will by no means pass away," we can take this literally and apply it chronologically.
How so? Well he mentions that the generation would not pass away but "heaven and earth" will pass away. Thus the generation that would see all these things would extend past when "heaven and earth" would end. The translation of this is that the end of that system of things, the system of things of the "gentile times" would indeed pass away before the last signs of that generation or that generation itself would pass away. That last generation of 80 years was from 1914 to 1994. But the "end of the gentile times" occurred in 1947, thus before the end of the last generation. Now doesn't that make more sense than thinking that the literal heaven and earth would pass away before the second coming? Or that heaven, where God dwells and the earth, which abides forever, would one day be no more? Of course not.
This addresses one of the fascinations but also complications of language and culture. Trying to understand some of the idioms and alleogories and colloquailisms used in the Bible that people back there understood in their time, that have no real meaning for us in our time, any more than someone saying today "You can reach me on my cell anytime!" when translated in any other time prior to the cellular phone would be understood as an isolated reference. Thus some effort needs to be made at the very hint of a possible contradiction or inconsistency to see if we can put ourselves into the cultural situation back then, that actual setting to help understand what is being said rather than going with the contradiction.
So when Jesus talks about it being harder for a rich man to enter heaven than a "camel" to pass through the eye of a needle, he's not talking about a literal 4-legged dromedary, he's talking about the colliqualism of a knot in the thread or when the thread bunches up behind the needle, the few strands that pass through followed by the bunched up thread not passing through resembling a camel with its small head and skinny neck being able to pass through small passages but not his entire body with that hump. Or when Christ talks about the pharisees straining out the gnat and gulping down a "camel" in their drink, he's not having us imagine a huge camel that might end up in some wine glass, but instead a very large horsefly, which they called a camelfly, "camel" for short, that would be gulped down. Thus the "camel" and the gnat are compared together as of the same things, only one really, really small and the other quite huge, but still quite possible to gulp down even if they choked on it. How can someone gulp down a literal camel? Still few people actually make the distinction. Likewise "heaven and earth" as a catch-phrase to describe the order of things is often misunderstood as a literal reference to the heavens and the literal earth, which it is not.
JC