Adam and Eve, at that time, lived under a state of innocence. God would regularly visit them, and they had an idyllic life. The nature of the forbidden fruit was actually explicitly laid out in the account of Genesis. It says that the tree was the "tree of the knowledge of good and evil." The tree represented the death of innocence. After they ate of the tree, God provided them with animal skins to replace their fig leaves. Animal skins would have by necessity required the death of an animal--the shedding of blood. The "Law" that came later, under Moses, was the codification of all the things humans would need to do in order to be accepted by God. But there's more. The law, just like the animal skin, was only a symbolic and temporary fix--it did not solve the essential problem. The problem was that man's nature had fallen from innocence.

The ultimate solution God provided to fix this problem was not a temporary or a symbolic one; it was a real solution. The solution was not to bring humanity back to a state of ignorance and naivety or to try to force the appearance of sinlessness onto humanity through a strict system of laws and mere external compliance. The solution was to bring humanity into a state of union with God with eyes wide open, a full communion of the natures of man and God. The solution God provided was that He Himself would take on humanity via incarnation, conquer its faults, be the sacrifice to purge and expiate sin (then literally rise from the dead 3 days later), and that His Spirit would be poured out on all who accept that sacrifice.