Separated from God and eternal life, man freely accepted communion with The Devil and so fell under his jurisdiction and became a slave to Sin and Death.
Man abandoned God, but God did not abandon man.
He made it possible for man to recreate and regenerate life by having children, therefore although a man dies, he passes on his human nature to another person.
If man did not die, Sin and Death would have become immortal and reigned forever and so union with God would have been impossible.
But this process of regeneration made it possible that man's nature did not die completely; it delayed the inevitable and final moment of man's final destruction, until God could put into motion His plan to save him from Death: man's last enemy.
We inherit the consequences of Adam's Original Sin because he is our father and so he passes on to all his children the fallen state of his human nature.
The New Adam
All of Adam's descendants until the coming of Jesus Christ, had lost the likeness of God and therefore the ability to acieve union with God. The only way to save man from Death and to unite him with God and eternal life, was to have someone break the chain of inheritance.
To do this God had to create a New Adam that would not inherit the consequences of Theology/Catechumens/The Fall, but at the same time he would have to have a common link with the rest of humanity.
Man is conceived through the seed of man and fallen nature is passed on through this process, so how did God solve this problem?
God willed that He would himself become a man and live as one of us.
This he did by taking flesh from the Virgin Mary who was herself born from a line of ancestors who were prepared by God until the right person was found who could give Him birth. Whatever preparation was needed, this in no way afected their Free Will: they could accept or reject God's will at any time.
Mary, born of the seed of man became the common link with the rest of humanity, right back to Adam. She lived without sin, choosing from her birth to be guided by the Holy Spirit, until God chose the right time for His incarnation.
Living without sin does not exempt someone from the consequences of the Original Sin, despite what recent Catholics say with their invention of The Immaculate Conception.
Christ is therefore the New Adam, He is God become man - but He was NOT subject to Original Sin. He was not created like the rest of mankind, but in a miraculous and mysterious was as we are told in the Annunciation story where the Angel Gabriel announces to Virgin Mary that the Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee. From His birth to His Crucifixion, Death and Resurrection, we learn all we need to know of His life as a man, in the Holy Gospels.
Death can only have a hold on someone if that person inherits or falls into Sin, because Death is the consequence of Sin.
Jesus Christ was free from all Sin and so when he was crucified and laid dead in the tomb, Death had no legal claim on Him, and so His body was resurrected and ascended into heaven.
Christ's human nature, free from Sin broke the barrier that separated us from God. The New Adam had pulled down the middle wall of a partition that had been erected by the fall of the Old Adam. In the same way we are all one and share in the fallen human nature or the Old Adam, we can now become one with the renewed and deified human nature of Christ, the New Adam.
next > Ascension of Christ
also > The Resurrection