In the same way that there is both disease and medicine, there definitely is both good and evil. Any less a statement is a mental irresponsibility, in which the task of finding true-value is aborted, and nothing remains but a half-formed identification.
Demons and the devilish do symbolize the element of evil, but their image has mostly served as an inaccuracy within society. But even the worst of the demonic one can fathom, may not be evil enough to bare truth about evil. Why is this so? Well, all things good can easily be made evil, through a slight tinkering of the clock-work. Such a deviation from true-nature -- would make the best into the worst. Evil is when the very best of all things becomes merely an infinitely cruel enemy. Simple and neutral beings cannot even have the capability to work what is evil, in the same way that an ant cannot know truth. Instead, the worst a simple or a neutral being could be for evil is fuel. Also, the ultimate evil knows truth. It knows much of what the innocent do not, but it uses its knowledge as a weapon, which degrades and defiles, instead of helping or preserving. Evil is a disease, a defect, and an imperfection. It is a super-disease, which becomes more terrible as it becomes more blessed. And the more powerful evil becomes, the more abusive it also becomes. In the same way that truly evil men have walked upon the earth, there are demons, in the sense that there is conscious physical energies which are really evil. The main sign of true-evil, is a force or pattern which is unhealthy for all beings, and would be unhealthy for any society, any organism, any structure.
Angels were once called the messengers of "God". Or, the ones baring some higher truth, some higher force, some higher importance. I advise thee to look beyond forms, and at least most will see, there is good beyond angels, and angels are less than the good which is beyond them. There is good; THEY would give thee something like a crown, something of higher value, above your head, which fits over your mind, and reminds you of what is truly important. The elementals of goodness -- are beyond a form, and they are perfection, or close to it. They make things complete, they make things progress, they make harmony. Some near them may have a strange shape, in which their heart is directly beside their brain, and they have a large mass near the shoulders, but they have no distanced head, and thus, mind and body are very very close to one-another. Each one when it is born, it can say: "I know exactly what I am". They are somewhere between a complete existence and a complete knowledge, but unending can their successions be, aswel. They are something like the griffin, for they are meant to both run and to fly. To become near to one, the becomer must put the value of incorruptibility above the values of intellect and strength, because evil only gets worse if it bends the mighty and the super-advanced.
Avoiding false-good? One of the first forms of false-good is oppression. In which the capacity for both good and bad is lobotomized. This sort of false-good says death is better than imperfection. But nature knows when death must be, and killers do not. Surely, it is better to have an imperfect friend than it is to have no friends at all, for at least when one has an imperfect friend, one can try to become more perfect with another. That is to say: Better to improve something than to have nothing.
Avoiding false-good? Imagine a passenger-plane, which was incompletely formed... It had many parts missing, and it flies up then down into tragic destruction. Thus also is the way in which incomplete knowledge flies. And then the ignorant fall terribly. A deformed air-plane would cause more harm than a deformed toy-truck. As I've said before, better becomes only worse if made evil. A false sense of what is good, will bare only false progress. A false sense of what is evil -- will only bring misguided hate upon the sick and the needy. No mighty one has any right to hate the old and the frail. No pure one has any right to hate the sick and the corrupt. The good shall heal the diseases, and the good shall support the best of the many. The good shall never destroy itself. The good shall not bring either slow-death or fast-death. The good shall instead make things as alive as possible, as full as possible, as whole as possible, for as long as possible.
The human sense of good and evil -- has been a key survival-mechanism for them. If they had no sense of good, they would have no medicine, no art, no knowledge, no love and no benefit. If they had no sense of evil, they would openly ignore all sorts of danger, all sorts of contamination, all sorts of loss. The only thing more evil than ignorance -- is a devious sadism.
Good and evil have been shunned as concepts, by some philosophers, due to the majority of these concepts being false, in society. Pleasure has been mistaken for good, and the hated have been mistaken for the evil. Pleasure is not truth, though. Pleasure connects, attaches, stimulates, draws in and controls. Pleasure can be either bad or good, depending upon where it is. And all things feared, all things hated, all things frowned upon, do not all have to be evil. In fact, what would a life be if it was full of fear, hate and frowning? That life would be deformed, sick, imperfect, and to some degree, evil.
Due to the imperative nature of organic existence, life is imposed and forced upon the inanimate, and in many cases, life is difficult. So long as it is alive, it need not be good or bad, says the Earth. And later, only through competition and though inter-connection could the better rise above the worst. But now, nature in herself has a great problem. That problem is: The old quantity destroying the new quality. It is easier to do bad than it is to do good, and the Earthly often does what is easiest for them, because life is a hardship and a chore for them.
The predator is not really bad, even though it kills without mercy. The predator takes only a few of the many, for itself, and it should take the vulnerable, the weak and the old. But the predator also gives back of itself, hopefully taking the quantity and giving the quality. And thus is the meaning of the predator: to take the lesser, and add it to the greater. And the herbivore is predator onto plants.
The terrible is jealous, old and wicked. It is no predator. It is, instead, the living catastrophe. It sees something better than itself, during infancy, and then it strikes down its superior before its superior could ever form. The terrible prevents creation beyond itself. The terrible is oppression, suppression and infection. The terrible is not efficient in any other way, other than its gage of evil is how efficiently it can waste and squander all of the very best and most sacred things ever to be near its grip. And this is evil. This is evil by true definition. This is when the greatest becomes the worst, for it stands above all things and prevents them from becoming better. Evil is the most powerful disease. Evil: efficient waste. And the truly good would be willing to give himself into what is better than himself, supporting and becoming the growth of superiority.