a choice that men were given at creation. to take from the tree of life! or the tree of the knowledge of good and evil. if adam and eve had taken from the tree of life first (which was offerred to them) then God wouldn't have said 'behold, the man has become like one of us, knowing good and evil (deciding for himself good and evil); and now, lest he stretch out his hand, and take also from the tree of life, and eat, and LIVE FOREVER.' so basically, as i understand it, we are not immortal since adam was banned from the tree by the angels that protected the garden afterwards. the tree was supplanted by Jesus Christ, who IS the 'living waters.'
in the New Testament, Jesus Christ says 'anyone who drinks of me, will LIVE FOREVER.' so i think that we do not have eternal life inherent in us already. the samaritan woman was surprised to be told about these 'living waters.' others had already asked 'how can a man be 'born again.' he said, except u be born of 'spirit' u cannot be. they contended - how can we get back inside the womb and be 'born again?' he mentions the correlation between 'blood and water' (which was given for us at the crucifixion) and the 'spirit and life.' if our physical life is in the blood - our spiritual life is in Christ Jesus.
if it was selfish to want to live forever - why would God offer it at creation? i think that death is what God did not want. sin and death are really what we should avoid - not life and everlasting life. in revelation 22:2 'in the middle of it's street (the street where the river of the water of LIFE, flowing from the throne of God and the Lamb) is and on either side of the river was the TREE OF LIFE.'
the same tree that was in the garden of eden. ....'bearing twelve kinds of fruit, yielding its fruit every month; and the leaves of the tree were for THE HEALING OF THE NATIONS.' i think this is very telling. the government of God will be SO DIFFERENT than what we have today. it will be FAIR. JUST. EQUITABLE. for everyone. noone will feel cheated. everyone will feel empowered. the nations will be shown the way of peace. noone will be warring. otherwise they would have been destroyed before the kingdom was set up. this kingdom is the kingdom of heaven. certain people are not allowed to enter in. not necessarily sinners - but those who do not accept Christ's atoning sacrifice (as i understand it). 22:14 'blessed are those who WASH THEIR ROBES, that they may have the right to the tree of life, and may enter by the gates unto the city.'