In general, churches portray the earth as a launching pad from which to leap into an eternity of heaven or hell. We don't. God did not put us on earth because he wanted us somewhere else. He wanted us here and he wanted humans to expand the boundaries of Eden to embrace the whole planet. He did not create humans to die at all, but to live indefinitely, which they would have done had they not rebelled against him.
The Genesis account tells, not of one tree, (the tree of the knowledge of good and bad) but of two. The one we don't hear much about is called the tree of life. They are both introduced to us in Gen 2:9:
Thus Jehovah God made to grow out of the ground every tree desirable to one’s sight and good for food and also the tree of life in the middle of the garden and the tree of the knowledge of good and bad.
Though real, neither tree conveys magical properties. Their qualities are symbolic. The tree of the knowledge of good and bad represents God's right to rule over his creation, that is, his right to determine what is "good and bad," as opposed to humans usurping that function. The second tree, the tree of life, represents God's guarantee of life. That guarantee was withdrawn after the first humans ate off the former tree, disobeying his direction and rejecting his rulership.
The original command given to Adam:
From every tree of the garden you may eat to satisfaction. But as for the tree of the knowledge of good and bad you must not eat from it, for in the day you eat from it you will positively die. Gen 2:16
They did eat from it, as noted, and so we come to the second tree:
And Jehovah God went on to say: “Here the man has become like one of us in knowing good and bad, and now in order that he may not put his hand out and actually take [fruit] also from the tree of life and eat and live to time indefinite,—” With that Jehovah God put him out of the garden of E´den to cultivate the ground from which he had been taken. And so he drove the man out....Gen 3:22-24
The point is that humans were designed to live on earth forever, to time indefinite. Death after 80 or 90 years was not God's idea.
This fits in very well with what we observe about ourselves. For example, we use (what is the correct percentage?) one tenth of one percent of our brain's capacity. How did that come to be? Evolution can hardly be responsible. In the absurdly unlikely event that super-brain storage could mutate into existence, natural selection dictates that it is passed on to progeny only if it offers a substantial edge in the fight for survival. But the bigger brain hard drive offers no such edge....we have already defined that it is unused. It's a bit like having a house the size of Europe when we only use 3000 square feet. Wouldn't you scratch your head and wonder what the realtor had in mind?
But if we recognize that we were created to live forever....well....then it all makes perfect sense. We would eventually find a use for all that brainpower.
That indefinite life was dependent on those first humans remaining in harmony with the Creator's purpose and design. Once that first couple pulled away....well....it's somewhat like a fan pulling itself out of it's wall socket. Those blades, spinning like mad, begin to slow and eventually stop. And it's hardly the fault of the wall socket, especially if you, the fan operator, were told to keep it plugged in.
But now, how will God yet achieve his original purpose towards earth and humankind? He will, of course. He has a plan set in motion, a plan hatched immediately upon that original rebellion.
It is cryptically referred to in Gen 3:15 [And I shall put enmity between you and the woman and between your seed and her seed. He will bruise you in the head and you will bruise him in the heel.] and is frequently discussed in the literature of Jehovah's Witnesses. The "plan" makes for lengthy discussion. Some of it is here: