No more philosophically profound, no grander or more graphic and suggestive type exists among the allegories of the World-religions than that of the two Brother-Powers of the Mazdean religion, called Ahura Mazda and Angra Mainyu, better known in their modernized form of Ormuzd and Ahriman. . . .
The two Powers are inseparable on our present plane and at this stage of evolution, and would be meaningless, one without the other. They are, therefore, the two opposite poles of the One Manifested Creative Power, whether the latter is viewed as a Universal Cosmic Force which builds worlds, or under its anthropomorphic aspect, when its vehicle is thinking man. For Ormuzd and Ahriman are the respective representatives of Good and Evil, of Light and Darkness, of the spiritual and the material elements in man, and also in the Universe and everything contained in it. -- H. P. Blavatsky
What is good? What is evil? Are they things-in-themselves, or are they conditions through which entities pass? Good is harmony because relative perfection, and evil is disharmony because imperfection; and these two, good and evil, insofar as we are concerned, apply solely to our hierarchy. Our 'good' is 'evil' to the entities existing in a superior hierarchy. Evil signifies a state of an entity or group of entities in greater or less degree opposing the forwards-moving evolutionary stream of life.
Whence comes the evil in the world, if the divine which is mightier than evil is everywhere? One would think from such a question that evil is an entity, a power or a force, which flows forth from the heart of some thing or being. On the contrary, it is merely the condition of an evolving entity which has not yet fully manifested the latent divinity at its core, and thus is inharmonious with its environment because of its imperfection.
Good is not created. Evil is not created. They are two poles of the same thing. There is no Devil in the universe, wrongly supposed to be the creator and arbiter of evil. Equally so, there is no God, wrongly supposed to be the creator and arbiter of good. It is all a question of growth. Human beings are evil entities when compared with the gods. The gods in their turn could be called evil by entities still loftier than they.
Good is not spirit, evil is not matter, the nether pole of spirit, because that would be saying that matter is essentially evil, which it is not. Evil, whether spiritual or material, is whatever is imperfect and passing through a phase of growing to something better. Neither matter nor spirit is in one or the other condition absolutely, and for eternity. A spiritual entity is evolving just as much as any material entity. Nevertheless, because spirit and spiritual beings are nearer to nature's heart, they are, collectively speaking, more perfect, therefore less evil than matter and material entities.
Evil per se does not become good per se, that is, one state does not become another state, the truth being that it is the evolving entity which passes from one state into another. Both good and evil are conditions of growth. This calls to mind the ancient theosophical and Christian -- expression concerning entities existing in a state of "spiritual wickedness" (Ephesians, 6: 12). Obviously, if those entities, although belonging to the spiritual realms, are imperfect and inharmonious there, they are 'evil' in that state. If entities, belonging to the state which we call relative perfection, exist harmoniously with surrounding beings, then they are entities of spiritual good. Harmony, law, order, peace, love: all these are conditions of entities who are in accord with the onward-flowing current of evolutionary growth. Such entities are more nearly at one with the heart of Being, and therefore endure.
It is the balance of spiritual and material existences -- the natural course of universal being -- which gives the diversity in the universe. There is no power (or powers) which keeps the universe either all good or all bad; for it is neither the one nor the other. Vast hierarchies are the universe, hierarchies on the invisible planes and likewise on that cross section we call our physical world; and it is the differences in evolutionary degree attained in these hierarchies and in the hosts of entities composing them which provide the vast diversity that the universe manifests. It can at no time be either all good or all bad, for it is perpetually advancing; and this marching army is without beginning and without ending.
A tidal wave comes in upon the land and sweeps twenty thousand human souls into the waters and drowns them. Is there therefore evil in the world? What brought that catastrophe about? Or again, an earthquake shakes down a city, and more than a hundred thousand perish. Is that evil per se? The earthquake is an event, as is the tidal wave. Nature's law is that effect succeeds cause. Nature is strictly harmonious at its core and through all its parts, and all its movings are towards a restoration of harmony -- which is equilibrium. What we sow, we shall reap. Nothing happens by chance. And if a person is caught by a tidal wave or killed in an earthquake, it is because he himself by his past karma has put himself in those surroundings. He is reaping what he has sown.
We should have a lunatic universe were karma nonexistent, if men could wreck the lives of others, and then escape scot-free. Nature is not so built. Man is a god in his inmost and, because he is linked with the divine elements as well as with all the other elements of the universe, what he does, nature reacts against. He has free will, and so reaps the consequences of all that he thinks and does and is. A man who works for brotherhood and kindliness has all nature's evolutionary stream with him; this brings strength and light and induces a cosmic expansion of his inner faculties. The man who works for hate, for selfish ends, who sets his puny will against the evolving river of lives, has all nature's incalculable weight pressing upon him. Such action on his part is imperfection, inharmony, and therefore evil.
Universal nature in manifestation is dual in character, divided into consciousness or the light side and matter or the dark side. Quoting from The Key to Theosophy (p. 112):
Light would be incomprehensible without darkness to make it manifest by contrast; good would be no longer good without evil to show the priceless nature of the boon; and so personal virtue could claim no merit, unless it had passed through the furnace of temptation.
The ancient Zoroastrian religion strongly emphasized this duality and this conception was very early taken over by the Christians. But when the cosmic unit passes into its pralaya, then good and evil vanish and are resolved back into the ineffable oneness of cosmic divinity -- to lie latent until the new term of manifestation as a universe begins.
Throughout the cosmos we see that evil is the conflict among entities, arising because of their as yet imperfectly developed spiritual powers. Applying this to man and his works, the conflict of human wills and intelligences which strive against each other, produces disharmony, pain, disease, and all the host of evils. Yet when we learn the lesson that our interests are one instead of diverse, we shall work together in a constantly increasing ratio as our spiritual understanding unfolds.