It's said that death came into the world due to the primary sin of Adam and Eve. But if you take a look around you notice that everything dies. From the little ants to the immense universe we live in. Then is it fair to say that the little ants and the planets, galaxies, the whole universe, all die because one guy ate a forbidden apple?
You mean the "happy fault of Adam"? It's not that bad, seriously it's unspeakably evil, but it's not the end of the world. It's really the beginning of the world, the first Covenant between God and man wasn't until after the fall
70 Beyond the witness to himself that God gives in created things, he manifested himself to our first parents, spoke to them and, after the fall, promised them salvation (cf. Gen 3:15) and offered them his covenant. (CCC 70)
So, no fall = no redemption. Take, you're pick - this is why we say God is good all the time!
It's funny. This question made me realize something I never noticed before. It's true. For almost nothing (a 'mere apple'), Adam knowingly threw away life, heaven, paradise, and eternal happiness - for the whole universe. This makes Adam's sin possibly the greatest ever committed. A million Hitlers could not sin in all their lives as much as Adam did in this one crime.
One sin, no matter how small is the closest thing man will approach the infinite for it shows disrespect to the only being who is infinite in goodness and glory. Therefore, the smallest sin can't be repaid in a thousand deaths of the universe. Even if all mankind, animals, forests, planets, etc., were to burn a thousand Hells, the penalty could never approach the infinitude of the crime because a crime is proportional to the object it offends. To cut off the leg of a centipede when angry is not as offensive as cutting off the leg of the American President's new born child in anger. Similarly, to disrespect God is greater than all crimes against all humans, for all of time.
Now to add to the infinitude of the smallest sin, the fact that Adam actually did not have a sinful compulsion and yet threw all of life away for just a stupid apple, who can comprehend or express the wickedness of it? We would be less foolish and evil to kill a whole nation with a nuclear bomb for the temptation of a jelly-bean.
Death, the cessation of life, and death, the forgetting or cessation or mortality of the immortal soul are two different things. The point in case here is the corruption and mortality of the immortal but passable soul. You can see Athanasius' 'On the Incarnation' about this. Humans are intended and made to be immortal. The immortality of the soul is of course not a form of self-existence but is so in connection with God, or as some say, 'immortal by grace'. So when you look at the death of say, a dog, it is not indicative of anything but that dogs die - it may be the case that dogs are made to die, but in any case, they do not seem to be aware of their mortality.
By the way, in patristic literature, this idea of cessation of life is connected with the bestial, or lowering of man from his proper rank to that of brute animals. So even early on you see that the death of plants, animals and so forth is not seen necessarily as a result of man's fall, but as the natural condition of such things, which man falls into in disobedience and separation from God. Thus while this may be natural for a plant or an animal, it is not so for man. Plants and some creatures also don't seem to be individual 'lives' in the same way people are; take for instance the grafting of plants together to form one seamless organism.
A second point, is that some think that the original creation, that of paradise, is entirely immortal just as man was immortal, but that in being cast our of paradise, man enters into a chaotic, death filled world, even as he himself becomes chaotic and death filled. This being so that he does not become as Satan is; disobedient, impassible and immortal.