In greek the adjective dead is nekros (νεκρός) and the noun is thanatos (θάνατος).
This is a natural event of life. It must be said clearly: biological death is not the result of sin. Biological life without death could not exist. Philosophically, death it is part of our finitude, it is a boundary, but it is not a punishment as would argue some fundamentalists. How can I say such a sentence if I want to be part of "Bible believers"1?
In Genesis 2,17 God says:
you must not eat from the tree of the knowledge of good and evil, for on the day you eat from it, you will certainly die.
This sentence finishes by
בְּיוֹם אֲכָלְךָ מִמֶּנּוּ--מוֹת תָּמוּת — Beyom ‘achâlechâ mimmènou mot tâmout
This "mot tâmout" could be translated : from death you will die. It is typical of semitic language to double important words to insist. But the repetition is not a simple stylistic effect as we can have in proverbs for example. As the continuation of the story shows, Adam and Eve eat the fruit of the forbiden tree. So then what happens? Well... they don't die! At least not physically. However they die spiritually as their behavior shows: they hide from God (3,8), and they are ashamed of themselves (of who they are, not about what they have done).
So being mortal is not a punishment, it is natural. Because if dying physically would be the penalty for sin, then it would be inconceivable that God would give a period of time before death (as in the Hebrew text it says "Beyom" literally: in the day when) and it would also be incomprehensible that Jesus as perfect Son of God could die even though he chooses it. Furthermore, it would be even more incomprehensible that if he died for us on a cross, we would continue to die after his sacrifice.
Nevertheless, death has a link with sin. Not as penalty but as a consequence. Let me explain:
Sin is not merely eating what is forbidden to eat. Sin is the desire to take God’s place as the serpent says (Genesis 3,4-5):
“No! You will certainly not die,” the serpent said to the woman. “In fact, God knows that when you eat it your eyes will be opened and you will be like God, knowing good and evil.”
The result of such an attitude of almightiness, is that humans have to find the solutions to existential problems by themselves (like the unforgiving servant in Matthew 18,28 who wants to pay back to his master (God) everything he owes, which in regard to his debt is impossible). And especially humans have to find a solution to face death by themselves. So death becomes an enemy. And enmity between man and death is the consequence of sin.
Of course, even if we think we are God, we are not! And there is no solution to fight our new enemy. Unless we abandon this attitude (which is called repentance).
Jesus said: (John 11,25-26)
I am the resurrection and the life. The one who believes in me, even if he dies, will live. Everyone who lives and believes in me will never die. Do you believe this?
This implies that if we want to live, we have to die first. This is dialectic language. And this is God’s teaching: if we are to understand it we have to accept a few paradoxes rooted in the abyssal difference between the nature of God and our own.
Now we can wonder about our destination when we die. We'll do this in the following sections.