According to the account of the fall in Genesis, one of the main effects of sin, perhaps the principal effect, was death. God assigns death as the reason that man should not eat of the tree of knowledge of good and evil: “You may freely eat of every tree of the garden; but of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat of it you shall die.” After Adam’s sin, chapter 3 ends with man’s exclusion from the garden and therefore from the tree of life:
Then the Lord God said, “See, the man has become like one of us, knowing good and evil; and now, he might reach out his hand and take also from the tree of life, and eat, and live forever”— therefore the Lord God sent him forth from the garden of Eden, to till the ground from which he was taken. He drove out the man; and at the east of the garden of Eden he placed the cherubim, and a sword flaming and turning to guard the way to the tree of life.
If you take Scripture as a whole and ask, “What is it about?”, one reasonable answer would be, “Sin, death, and overcoming them.” Thus we have the account here where sin and death originate, basically at the very beginning of the Bible. And the last chapter of the last book of the Bible begins thus:
Then the angel showed me the river of the water of life, bright as crystal, flowing from the throne of God and of the Lamb through the middle of the street of the city. On either side of the river is the tree of life with its twelve kinds of fruit, producing its fruit each month; and the leaves of the tree are for the healing of the nations. Nothing accursed will be found there any more. But the throne of God and of the Lamb will be in it, and his servants will worship him; they will see his face, and his name will be on their foreheads. And there will be no more night; they need no light of lamp or sun, for the Lord God will be their light, and they will reign forever and ever.
The tree of life has ultimately been restored to mankind. St. John adds a final warning:
I warn everyone who hears the words of the prophecy of this book: if anyone adds to them, God will add to that person the plagues described in this book; if anyone takes away from the words of the book of this prophecy, God will take away that person’s share in the tree of life and in the holy city, which are described in this book.
The worst thing that can happen to you is to be deprived of a share in the tree of life.
It would be easy to show that this theme runs through Scripture from beginning to end. Thus for example Deuteronomy 30 concludes:
See, I have set before you today life and prosperity, death and adversity. If you obey the commandments of the Lord your God that I am commanding you today, by loving the Lord your God, walking in his ways, and observing his commandments, decrees, and ordinances, then you shall live and become numerous, and the Lord your God will bless you in the land that you are entering to possess. But if your heart turns away and you do not hear, but are led astray to bow down to other gods and serve them, I declare to you today that you shall perish; you shall not live long in the land that you are crossing the Jordan to enter and possess. I call heaven and earth to witness against you today that I have set before you life and death, blessings and curses. Choose life so that you and your descendants may live, loving the Lord your God, obeying him, and holding fast to him; for that means life to you and length of days, so that you may live in the land that the Lord swore to give to your ancestors, to Abraham, to Isaac, and to Jacob.
Here we see that fidelity to God leads to life, or to overcoming death, while infidelity leads to death. But this is a very imperfect overcoming of death, since at most one can “live long in the land,” and one still dies in the end. Consequently the book of Ecclesiastes complains,
Vanity of vanities, says the Teacher,
vanity of vanities! All is vanity.
What do people gain from all the toil
at which they toil under the sun?
A generation goes, and a generation comes,
but the earth remains forever.
Later, he points out that doing good and doing evil appear to make no difference at all in the end:
Then I said to myself, “What happens to the fool will happen to me also; why then have I been so very wise?” And I said to myself that this also is vanity. For there is no enduring remembrance of the wise or of fools, seeing that in the days to come all will have been long forgotten. How can the wise die just like fools? So I hated life, because what is done under the sun was grievous to me; for all is vanity and a chasing after wind.
In the New Testament, St. Paul gives a theological account of overcoming death:
Therefore, just as sin came into the world through one man, and death came through sin, and so death spread to all because all have sinned— sin was indeed in the world before the law, but sin is not reckoned when there is no law. Yet death exercised dominion from Adam to Moses, even over those whose sins were not like the transgression of Adam, who is a type of the one who was to come.
But the free gift is not like the trespass. For if the many died through the one man’s trespass, much more surely have the grace of God and the free gift in the grace of the one man, Jesus Christ, abounded for the many. And the free gift is not like the effect of the one man’s sin. For the judgment following one trespass brought condemnation, but the free gift following many trespasses brings justification. If, because of the one man’s trespass, death exercised dominion through that one, much more surely will those who receive the abundance of grace and the free gift of righteousness exercise dominion in life through the one man, Jesus Christ.
Therefore just as one man’s trespass led to condemnation for all, so one man’s act of righteousness leads to justification and life for all. For just as by the one man’s disobedience the many were made sinners, so by the one man’s obedience the many will be made righteous. But law came in, with the result that the trespass multiplied; but where sin increased, grace abounded all the more, so that, just as sin exercised dominion in death, so grace might also exercise dominion through justification leading to eternal life through Jesus Christ our Lord.
One might understand many of these things in reference to a spiritual life, but in his first letter to the Corinthians, St. Paul makes clear that a true overcoming of death requires a bodily resurrection:
Now if Christ is proclaimed as raised from the dead, how can some of you say there is no resurrection of the dead? If there is no resurrection of the dead, then Christ has not been raised; and if Christ has not been raised, then our proclamation has been in vain and your faith has been in vain. We are even found to be misrepresenting God, because we testified of God that he raised Christ—whom he did not raise if it is true that the dead are not raised. For if the dead are not raised, then Christ has not been raised. If Christ has not been raised, your faith is futile and you are still in your sins. Then those also who have died in Christ have perished. If for this life only we have hoped in Christ, we are of all people most to be pitied.
But in fact Christ has been raised from the dead, the first fruits of those who have died. For since death came through a human being, the resurrection of the dead has also come through a human being; for as all die in Adam, so all will be made alive in Christ. But each in his own order: Christ the first fruits, then at his coming those who belong to Christ. Then comes the end, when he hands over the kingdom to God the Father, after he has destroyed every ruler and every authority and power. For he must reign until he has put all his enemies under his feet. The last enemy to be destroyed is death.
We could many more indications of the same thing. The Bible as a whole can be seen as an account of the origin of death and of how it is to be overcome.