Original reality is by its nature "Good" which is to say benign since it cannot and did not and will not self-destruct (is not malign), or else it would never have "manifested", which is to say that taken to infinitized understandings of finite notions of benign and malign, there is no way that malignancy can be at all. Also, it would never have manifested anything else since it is malignant and cannot even offer temporary beneficence. It cannot even be sustained in the longrun, since there are no resources it wouldn't destroy in its greedy and wasteful, stupid destructiveness. It's ideal state would be to have no challengers to its existence, and to exist alone, but that couldn't be since it must have something to harm in order to exist, since in the hypothesis it is evil to be, or exist, and evil implies the harming of something. If something else, then it wasn't the original being. If itself, it wouldn't exist. If another being fundamentally existed, it must be fundamentally different, and the fundamental difference is to be benign rather than malign. If it existed at he same time it would have been exhausted by the destructive being before any other beings could have manifested since infinite struggles would have to be resolved before finite ones could manifest, qualities before quantities. Yet if it came into being AFTER benign being it could be understood since it is parasitic at best. How a parasite could manage to come into being is the only real question, but let's just say that, temporarily, God was TOO generous, TOO "Good", TOO Benign, and had to deal with a being that was willing to take advantage of it due to being in some way accidentally and irreparably deficient in some aspect of its consciousness, so that we now have the manifest world here in this tiny sector of reality which we see today. If it came from the top down then we know why NO world would exist, much less a world with a mixture of good and evil. If it came from the bottom up it wouldn't have gotten any steam long enough to take over a whole sector of reality, to say nothing of overpowering other minds into its vile realm and holding them hostages of torture for eons. It had to have manifested from a being which existed somewhere in the middle of the hierarchy, probably on a low end sufficiently close to our level so as to be "experimental" or "novel", and yet high enough to have had a chance to use a really large quantity of power over a wide area of creation and so as to be able to entrap a large number of considerably powerful minds who would not willingly submit or at least not without sufficient deception, which still takes a lot of power in those cases.
In this context evil is whatever goes along with, or was originally created by this fraudulent, murderous, deceptive and devouring mind which seemed to literally INVENT such antiqualities. In this fraudulent world Good beings are always here against their will and so deception had to be the norm here. Good beings, here, are the only beings who TRULY want to be good, which means not only to "be nice and play by the rules" in this world. Actually it often means to do otherwise, because values in this world are all sub-realized falsifications or compromised relativities.
Based on this you will KNOW them, look at the manner and results of their actions, and the reasons, not as they give them, but as you find them by the Truth within yourself. If your inner Truth is that you are a Good being, you will be repulsed by the fruit of beings unlike you, and attracted to those of beings of your kind, and no matter what the outer forms you will smell the stench of evil and the fragrance of goodness with the nose of your heart, unfailingly. Unless you foolishly ignore it for too long, in too many lifetimes... So fight the good fight, call a spade a spade, and do what you know inside yourself is right. There are TWO SIDES and ONLY two sides. One of them IS evil, the other GOOD. The former is parasitic on the latter, and the latter will rebel against that parasitism, in both cases this is ALWAYS true. That's how you will DISTINGUISH them... Finally, based upon whether you are able to KNOW them and DISTINGUISH them, you will MANIFEST BEING one of them.
These are metaphysical facts and don't depend on your or anyone else's point of view. Actually quite the reverse... The ability to understand this point of view as I here express it is dependent upon which of these types of entities a person is... Ontology is unified with axiology, epistemology is simply a byproduct of beings being themselves in world where knowing the Truth bears the resistance of deceptions and lies. Nothing could be more antivalent than these two types of beings, such that they are morally different, and so even knowledge is split right down the middle...
Being is moral being, and it is of two sorts, so knowing this is the goal of True beings, hiding this is the goal of false beings, and evil is the intention of false beings who wish to rob good beings of their spiritual goods, their Glory and Wisdom, by means of falsified economies of interaction which wrest from them their energy into corrupt forms digestible by those who steal them.