We agree since Adam and Eve did sin before becoming being sinners you can sin before becoming a sinner, so does that not mean our nature would not have to change?
No I would not say that. A & E became sinners the moment they sinned; it was one and the same moment. The same way we close our eyes when we blink, the one doesn't precede the other. Not so for you and me though. We are 'sinners' at the moment of conception and if delivered (after 9 months) will not only go on to sin, but to delight in it. That's our nature. And it explains why Christ said "Ye must be born again".
There is an added problem here: If Adam and Eve had some better nature then we have today that would not be fair and just of God, yet God is totally fair and just?
The vessel that came fresh from the Potter's hands was not marred. It became marred when something from the outside was introduced (sin)...and the offspring from that vessel was marred as well.
God needed to address one big question everyone seems to ask at least some time in their life: How could a Loving God allow _____ to happen?
The simple answer is this: If God were to have a creature with whom He could commune while "walking in the garden in the cool of the day", He must give that creature the capacity to obey/disobey Him in and of himself; otherwise there could be no such true fellowship.
That goes back to the Parable of the wicked Servant (Matt. 18) which I have been trying to get you to address. As you say:
a pardon refused is no pardon at all. In the Parable of Matt 18 the servant never asked for forgiveness (pardon) but just time to pay the (unbelievable huge) debt back and went on to say he would pay it back.
As I suggested before...do not make the mistake of building a doctrine around a parable...even the beautiful types such as Joseph and Isaac fall short of presenting the full picture alluded to. As to gaining Salvation, there is no possibility you or I could pay any of the great debt we owe.
The Father allowed the prodigal son to reach the very bottom, bring him to his senses, so did sin help in that case?
No, sin did not 'help', it hindered. It was the sin of wanton self-centeredness that got the young son into trouble; it was a troubled conscience, a repugnance of his current situation, and a pleasant memory of a loving father that brought him to repentence. Sin doesen't bring anyone to repentance; it is the realized terribleness of sin and a desire to be shed of it that brings one to seek for a deliverance.
