Does the earth abide forever?

Great question.

First, in context, it might be worth mentioning that Ecclesiastes is not asserting that the earth will "never end" (it will always continue in some form). Rather, it is contrasting the ephemeral nature of humanity with the perpetual nature of the world. It is acknowledging what has been true in the past, and saying that this will continue to be true in the future. However, it does not promise that this will always be true. In fact, we know that eventually it will radically change. After all, when Jesus returns, the generations will no longer come and go - death itself will die. There is no reason to imagine that Ecclesiastes is denying future judgment or changes that might come as a result of God's intervention in the world (e.g., judgment, renewal). In fact, the closing verse of the book reminds us specifically that divine judgment is coming - "For God will bring every deed into judgment, including every hidden thing, whether it is good or evil" (Eccl. 12:14).

Second, the definition of "forever" is also flexible. It does not always mean "never ending." Often it just means "a long, long time." It can also mean "perpetually," as in, "until something big changes." And like most things in the Bible, statements about things that last "forever" include the implicit caveat that God can change them if He wants to. A familiar verse to most is Psalms 23:6. We have heard it referred to in numerous funerals, normally in the context of someone dwelling with the Lord in a "never ending" way, etc. The Psalmist states, "Surely goodness and love will follow me all the days of my life, and I will dwell in the house of the LORD forever." While a Christian DOES dwell with the Lord "forever" (never-ending), the context of Psalms 23:6, does NOT mean "never ending," but 'length of days,' which parallels "all the days of my life" in the first part of the verse.

Third, in addition to the above facts, NEW in Greek does not always mean "brand new"; it sometimes means RENEWED (new nature or quality). God says, "I am making everything new!" (Rev. 21:5).The vision of Revelation 21 reveals an earth with no sin and no effects of sin: no pain, tears which have been wiped away, no suffering; no death or destruction; no evil. However, was this not the way it was in the very beginning (Gen. 1-2) BEFORE the Fall, BEFORE the curse (Gen. 3)? There is a grand new beginning. However, will God begin "completely over"? Did God's first plan really fail, or being omniscient, was this his plan all along; that is with a pause for the Fall, and then to purify and cleanse that which fell? Do we not serve God who called order from chaos in the very beginning? See Genesis 1.

Revelation 21 implies that this world is to be restored or renewed taking on a new nature or quality, rather than a brand new and completely different earth. The radical change is so different that the term ba'ra (Isa 65:17; cf. Gen 1:1) can be used to describe it. So, when we understand the Bible's proper use and meaning of certain terms, Ecclesiastes 1:4, "Generations come and generations go, but the earth remains forever" does not contradict, Isaiah 65:17, "Behold, I will create a new [renewed] heavens and a new earth. The former things will not be remembered, nor will they come to mind" (cg. Rev. 21:5, etc.).

In essence, the earth remains forever, just not in the same exact form.

Fourth, some teach that 2 Peter 3:10-12 appears to refer to the destruction of the world with fire literally melting the earth; total annihilation. But when read in the context of 2 Peter 3:6 which mentions Noah's flood; the earth still exists, but in a different form. 2 Peter 3:10-12 appears to be a description of two different dimensions being joined together - the divine with the renewed earth (Rev. 21). The question to ask is whether the fire of judgment will completely annihilate or just purify the world? In Scripture, the fire of judgment destroys that which is evil, but it also purifies what is good ("If what he has built survives"; 1 Cor. 3:10-15). Ask yourself, why would all creation be groaning for the manifestation of the sons of God if ALL creation, without exception, was only to be completely annihilated - literally melted with fire (2 Pet. 3:10-12)? As Paul writes in Romans 8:20-22:

For the creation was subjected to frustration, not by its own choice, but by the will of the one who subjected it, in hope that the creation itself will be liberated from its bondage to decay and brought into the glorious freedom of the children of God. We know that the whole creation has been groaning as in the pains of childbirth right up to the present time.

Another argument goes, that if ALL the elect - without exception - are going to be BRAND NEW - this means ANOTHER new person receives the fruits of their labors. This type of injustice isn't part of God's economy. It is more biblical to understand that God's church will be RENEWED (this mortal shall put on immortality and this corruptible, incorruption - 1 Cor. 15, etc.); shall we not be made like Christ (1 John 3:2)? Though renewed, people still recognized Christ after his resurrection (cg. Thomas, the disciples on the Road to Emmaus, beside the Sea of Galilee to Peter, and after his ascension on the Damascus Road to Saul of Tarsus, etc.).

So yes, the earth is forever and ever and so are the saints that'll inhabit it - just not in the same way we know it now! Though things will be NEW, there will still be a relationship with the OLD (how related we really do not 'fully' know) - therefore "renewed" is a better term for understanding these things.