In Genesis 3 we learn of what is often called the fall of humankind. Before this point there was no sin - at least in this world - and so no corruption or decay. Presumably nothing had died, although that is a difficult idea. Adam is clearly placed in the Garden God created as a representative of humankind. He is the obvious candidate as he is the first man and no doubt the best. What happens, however, is that he disobeys God and so sins. Once he sins, everything changes.
God makes a positive law that Adam is not to eat of a certain tree, the moment he does so, he has sinned. What led to the sin? First, there is the activity of Satan who hijacks the snake. Secondly, there is the vulnerability of Eve, who Adam is meant to protect. Instead of doing that, he deliberately follows Eve's lead and sins. That sin dooms all humankind, his descendants, and drags all of creation into a fallen state so that nothing is the same again. Weeds grow where they are not wanted, we sweat and toil, everything becomes subject to decay. There is suffering.
The fall makes no sense. It is a species of madness where all right reason and sense goes out of the window. The consequences are far reaching and eternal. There is not a problem in the world that cannot be traced back to the fall in some way or another.
There seems to be no way out if it and yet even in Genesis 3 we read of the sweat of man's brow, the brow being what keeps the sweat from the eyes, and of the crushing of Satan's seed though at the cost of the bruising of the seed of man's head. God also provides skins for the couple to cover their nakedness, though clearly at the cost of the lives of certain animals.
