CN, it is in this environment, within which the Lord knew in advance what was going to transpire, that He intentionally introduced the elements He knew would bring about the result we have today.
You see, it violates the sensibilities of many religious thinking people to dare approach the realization that the Lord orchestrated into existence a number of elements that ensured the outcome. By that means, the flow of events slowly moved toward the environment, which we call sin, would become the very acid test bed for separating the sheep from the goats. That theme, therefore, has far reaching implications than many are willing to traipse.
Now, granted, that doesn't remove from mankind his responsibility for his sins, but it is the presence and commission of sin that we all are tested for what we're made of. Most choose the way of sin, thinking that they can just enjoy the pleasures of this world and there be no consequences resulting from their personal responsibility for the choices they make. Sir Frederick Hoyle made that abundantly clear when he was president of UNESCO back in the 70's.
That serpent was in that garden because that's exactly where the Lord wanted it. That tree of knowledge of good and evil was in that garden because that's exactly where the Lord wanted it.
The uplifting Truth in all this is that the Lord took FULL responsibility for the outcome He knew would result from His planting in that garden the very stimuli and Law that brought about this marvelous and abundant blessing of His sacrifice for us all.
MM