The Kabbalists devote a great deal of time trying to assess the effects of the sin of Adam and Eve and the serpent. It is clear that the world would have been totally different had they listened to Hashem. The consensus is that the most obvious difference would have been that people would not have died. The entire story is very difficult to comprehend. The שני לוחות הברית is of the opinion that what motivated Eve is that she wanted to be like Hashem Himself. It was as if the snake convinced her that if she thought the Garden of Eden was special, imagine what it would be like to actually resemble G-d! It was a kind of lust that allowed her to stumble. The Torah tells us that Hashem made them כתנות עור, clothing of leather skins. Before the sin, they were clothed with כתנות אור, coverings of light. This was an indication of the high level they were on before the sin. The nation returned to this high level at Mount Sinai, only to fall again with the sin of the Golden Calf. Kind of a mystical approach to a well known biblical story.