Garden of Eden before the fall, Adam and Eve were created to be immortals, just like the angels.
God said: “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 in the day that you eat of it you shall surely die.” Genesis 2:16-17
They disobeyed, and did die. Adam lived over 900 years and died.
Then more disobedience and sin plagued mankind. They continually did evil. The fallen angels taught them technology, science and witchcraft. Some men spent a life time (500 to 800 years) in developing evil sciences. They had time to research, test, implement, improve all sorts of techs and science. They even learned and practiced genetic modifications on men and animals.
Then God decided to wipe it all out: THE FLOOD.
God said said, “My Spirit shall not strive with man forever, for he is indeed flesh; yet his days shall be one hundred and twenty years.” Genesis 6:3
This is how today almost none live more than 120 years.
Zechariah 14:1 Behold, the day of the Lord is coming,
When Christ returns to make the world his Millennial Kingdom to Reign on earth as King of kings, the curse of 120 years will be lifted and men once more will live nearly a thousand years, that is if they don't sin. "the wages of sin is death" Romans 6:23
Then will come the ultimate and last test for humanity, when Satan and his fallen angels are released to deceive mankind. Some will (to hard for them to live by God's laws) war against God, others will remain faithful. What will follow is Judgement Day: Lake of Fire or Life Eternal as God intended when he created MAN.
Revelation 20
And God will live among his people.
