God, apparently, was the root of all evil.  It happened like this.  When God created the universe, including human beings, He gave them the gift of innocence and purity and simultaneously, freedom of choice.   But this meant that they were completely unaware that their actions had any moral implications.  They were incapable of forming what we call in the common law, “a guilty intent”, since they had no clue about was right or wrong.
 

At the same time, God gave Satan the mandate to be lead prosecutor for crimes committed by any humans.
 

From the beginning, then, there was a flaw in the scheme of things.  How could Satan prosecute anyone who could never be shown to have “mens rea”, a guilty mind?
 

All that Satan could do was to show that humans had disobeyed the law.  So this is what he did.   He used the snake to tempt Adam and Eve to disobey a direct command from the Lord.  He seduced them into eating the fruit of the Tree of Knowledge of Good and Evil.  At the time, there was nothing particularly sinister about this seduction since Satan did not use his left hand, and indeed, as a snake, used no hands at all.  Since those involved in the transgression had no knowledge of good and evil before they ate of the fruit, how could they be considered as guilty of a crime? 
 

Perhaps the problem was that God had created an entity that was too zealous in the execution of his duties.   Satan went out of his way to create a condition of transgression, even though he doubtless felt ahead of time, that this was a useless exercise.  Man was by his nature, innocent.  What could he be convicted of?  Yet Satan proceeded with his job, even though he knew that his efforts would be fruitless.  To remedy this shortcoming, Satan ensured that a fruit was involved, thus rendering his actions, not fruitless, but fruitful.
 

The upshot of this tragedy of errors, was that Adam and Eve acquired the capacity for a guilty mind, which they had not had before they had eaten the fruit.  Their crime was therefore not the eating of the fruit of the forbidden tree.   In a real sense, they did not know it was “wrong” before they ate it but only after.   No, their crime was blaming someone else for their actions afterward.   At that point, they had acquired a moral sense, were conscious of their individual responsibility and had only to tell God that they had chosen to eat the fruit because they had no understanding that this was “wrong”.  Indeed, they had not known what the word “wrong” meant.  Satan would have had to retire to cook up some other scheme.
 

But Satan had in fact succeeded.  Once Adam and Eve acquired the capacity for a guilty mind, then any transgression was open to prosecution and conviction.  With their new consciousness, both Adam and Eve started to feel guilty for disobeying a law, and instead of telling the truth, tried to mitigate their responsibility by blaming someone else.  “The woman made me do it,” says Adam.  “The snake made me do it,” says Eve.
 

Making excuses for breaking the law is the original sin.  It has led us as human beings to commit the most unimaginable atrocities over the years and in all cases, there are excuses and rationales offered up.   Why did you kill the Jews?  I had to because they threatened me.   How?  Well, uh, uh, they tried to steal all my money.  They steal children and use their blood in sacrifices.  They are evil and hate all human beings.  In fact, they aren’t human themselves….., etc.
 

One could argue, perhaps, that without that capacity to feel guilty, we would not be human and that God knew what he was doing when he created Satan as an essential tool to kick start the fully human experience of life, of individual responsibility and culpability.
 

Did even God foresee the human reaction to accusation, where we excuse all our own acts and rationalize them?  I think perhaps not.  That’s what makes this sin, the most original.