The Bible has much to say concerning the subject of death. It tells us how death originated, and how and why it is passed on.
                                                   
Paradise
  
The Bible says that the heavens and earth were a direct result of the supernatural creation by Almighty God. The crown of God's creation was humanity - man and woman. God created them in His image and placed them in a perfect environment. The Bible says concerning the creation,

Then God saw everything that He had made, and indeed it was very good (Genesis 1:31).

This was a world with no pain, no sickness, and no death. God's world was perfect.
                                             
Warning
 
There was only one thing humanity was not allowed to do - to eat of the tree of knowledge of good and evil.

And the Lord God commanded the man, saying,  'Of every tree of the garden you may freely eat; but of the tree of the knowledge of good and evil you shall not eat, for when you eat of it you shall surely die' (Genesis 2:16,17).

The Lord put restrictions upon Adam and Eve which required obedience to His will. God made it clear that disobedience would result in the death of the man and the woman. They would live as long as they remained obedient.
                                    
Be As God
   
God gave humanity the opportunity to chose their own fate.  The Bible says, the tempter, Satan, appeared in the form of a serpent and told them they could be like God if they only would eat from the forbidden tree.

Now the serpent was more cunning than any beast of the field which the Lord God had made. And he said to the woman,  'Has God indeed said, 'You shall not eat of every tree of the garden? . . . For God knows that when you eat of it your eyes will be opened and you will be like God, knowing good and evil' (Genesis 3:1,5).

                       
Paradise Lost     
  
The Bible says that humanity fell from their perfect state. Ignoring God's warning, Adam and Eve sinned by eating the forbidden fruit.

So when the woman saw that the tree was good for food, that it was pleasant to the eyes, and a tree desirable to make one wise, she took of its fruit and ate. She also gave to her husband with her, and he ate (Genesis 3:6).

The result was judgment pronounced by God.
                              
On Womanhood
 
The judgment on the woman concerned the birth process as well as her submissive role to her husband.

To the woman He said: I will greatly multiply your sorrow and your conception; in pain you shall bring forth children; your desire shall be for your husband, and he shall rule over you (Genesis 3:16).

                           
On Manhood    
 
The judgment on the male concerned work.

Cursed is the ground for your sake; in toil you shall eat of it all the days of your life. Both thorns and thistles it shall bring forth for you, and you shall eat the herb of the field (Genesis 3:17,18).                 

                          
Death Is The Result
 
Not only were the couple banished from paradise, but physical death was now the result.  

In the sweat of your face you shall eat bread till you return to the ground, for out of it you were taken; for dust you are, and to dust you shall return (Genesis 3:19).

  
Death was now passed on to everyone. The Apostle Paul says.

For since by man came death.  .  .  For as Adam all die (1 Corinthians 15:21-22).

All Judged

In addition, all people are to be judged. The writer to the Hebrews declared.

And just as it is appointed for mortals to die once, and after that the judgment (Hebrews 9:27).

Spread Of Death

The New Testament commenting on the spread of sin and death says.

For all have sinned and fall short of the glory of God (Romans 3:23).

The reason for sin and death is traced back to Adam.

Therefore, just as through one person sin entered the world, and death through sin, and thus death spread to all humanity because all sinned (Romans 5:12).

Adam's disobedience caused the sin nature to be passed on to all of us.

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 (Romans 5:19).

The final result will be death - the separation from God.

For the wages of sin is death (Romans 6:23).

Clearly, death is a result of sin and it is passed on to all of us.

First And Last Effect

Death was the first outward effect of sin. God told Adam and Eve.

But you must not eat from the tree of the knowledge of good and evil, for when you eat of it you will surely die (Genesis 2:17).

Death will be the last thing from which believers are saved.

The last enemy to be destroyed is death (1 Corinthians 15:26).

Normal And Abnormal

Depending upon the perspective, death is both normal and abnormal. Death is normal in the sense that it is the way life ends for humans. Humans who are made from dust, return to dust. The exceptions are when someone dies violently, prematurely, or without an heir. In these cases death is not the normal end.

Abnormal

There is also the abnormal sense of death. From the account in Genesis, we discover that death is something that is abnormal - it was never God's original intention or design. Death came as a result of the choice of the first human pair to commit sin. Humans were created to live, not to die. Death came as a result of judgment for sin.

Summary

1.  In the original creation of God there was no death. Everything was perfect.

2.  God warned Adam and Eve that disobedience to His commandment would result in their death.

3.  Satan, the tempter, enticed Eve to eat the forbidden fruit.

4.  After Adam and Eve ate the forbidden fruit God pronounced judgment upon them. This judgment included death.

5.  Death was passed on to all humans as a judgment for the sin of Adam and Eve.

6.  Death, therefore, is something abnormal. God created humans to live, not die.