The Fall and Redemption

Adam before the Fall possessed all the essences of human nature.
In addition, he was given bodily immortality as a special gift.
He was in intimate union with God: ( He was in sanctifying grace) and possessed free will in his soul : he was free to obey or disobey God.
He and Eve were in a state of human happiness.
(The Angels had undergone a similar test of their fidelity)
Adam’s obligation was to know, love and serve God on earth so that he could be happy with Him forever in Heaven.
However, Adam’s free-will had to undergo a test that would prove his fidelity to God.

Did he love and would he serve God.? : was he prepared to obey God or would he choose the Evil One?
In response to Eve’s urgings and Satan’s tempting, Adam disobeyed a clear command of God.

Following the Fall Adam still possessed all the essences of human nature.
However, he was no longer in intimate union with God.
His intellect was darkened.
His will was weakened.
The gift of bodily immortality was taken back from him and he was now faced with the inevitability of bodily death.

Adam’s descendants suffered from Adam’s rebellion by the same loss of union with God, darkening of intellect, weakening of will, and loss of the gift of bodily immortality.
Why did Adam’s descendants have to be implicated in Adam’s sin?
Because they too have free will and have to choose God rather than Satan. Like Adam they too have to be tested.

But why was Adam tested only once and condemned while his descendants have life-times of unknown durations to be tested and to show their love for God.? Adam and (the Angels) were tested once only because they possessed perfection of intellect and will and had no excuse for their infidelity : no weakness that might mitigate their crime.

Despite his mitigating excuse, man after Adam was not fit to enter into close union with God. This would require that man’s failures and sins had to be repented by man and forgiven by God. Simple repentence by man, however, would not be enough to satisfy God’s justice because of the enormity of the offence and insult to God that every sin constitutes.
Redemption was needed whereby God, the Son, would become human and on behalf of man would seek forgiveness for all of humanity’s sins. As it is God who thus acts on man’s behalf, forgiveness (following individual repentance) is assured to all who seek it in the prescribed manner.

It is not known what would happen to Adam and his descendants when they died if Redemption had not occurred. Would each and everyone through history go to Hell or some other place like Purgatory since Heaven was closed to them?
With the reality of the unlimited love God has for everyone He created, one can understand why He would do everything necessary to save us, everything except interference with our free will.