EVIL STUDIED FROM DIFFERENT ANGLES Part One
released 13-04-2008 to firstname.lastname@example.org
Mahatma Letter CXXXIV
We do not find it either necessary or profitable to lose our time waging war to the unprogressed Planetaries who delight in personating gods and sometimes well known characters that have lived on earth. There are Dhyan-Chohans and "Chohans of Darkness," not what they term devils but imperfect "Intelligences" who have never been born on this or any other earth or sphere no more than the "Dhyan Chohans" have and who will never belong to the "builders of the Universe," the pure Planetary Intelligences, who preside at every Manvantara while the Dark Chohans preside at the Pralayas. Explain this to Mr. Sinnett (I CAN'T) -- tell him to p.463
read over what I said to them in the few things I have explained to Mr. Hume; and let him remember that as all in this universe is contrast (I cannot translate it better) so the light of the Dhyan Chohans and their pure intelligence is contrasted by the "Ma-Mo Chohans" -- and their destructive intelligence. These are the gods the Hindus and Christians and Mahomed and all others of bigoted religions and sects worship; and so long as their influence is upon their devotees we would no more think of associating with or counteracting them in their work than we do the Red-Caps on earth whose evil results we try to palliate but whose work we have no right to meddle with so long as they do not cross our path. (You will not understand this, I suppose. But think well over it and you will. M. means here, that they have no right or even power to go against the natural or that work which is prescribed to each class of beings or existing things by the law of nature. The Brothers, for instance could prolong life but they could not destroy death, not even for themselves. They can to a degree palliate evil and relieve suffering; they could not destroy evil. No more can the Dhyan Chohans impede the work of the Mamo Chohans, for their Law is darkness, ignorance, destruction etc., as that of the former is Light, knowledge and creation. The Dhyan Chohans answer to Buddh, Divine Wisdom and Life in blissful knowledge, and the Ma-mos are the personification in nature of Shiva, Jehovah and other invented monsters with Ignorance at their tail).
From: Letters of Occultism by Alice Bailey
The Kinds of Obsessing Entities
These are too numerous to mention in detail but I might enumerate a few.
Discarnate entities of a low order awaiting incarnation, and who see, in cases one and two, their wanted opportunity.
Suicides, anxious to undo the deed and to again get into contact with earth.
Earth-bound spirits, good and bad, who from anxiety over loved ones, over their business affairs, or eager to do some wrong or to undo some evil act, rush in and take possession of cases one and two.
Dark Brothers as aforesaid, who avail themselves principally of the third and fourth cases already cited. They require highly developed bodies, having no use for weak or unrefined bodies. In case three the weakness is entirely relative, due to over-accentuation of the mental vehicle.
Elementals and subhuman entities of a malicious nature who rush in on the slightest opportunity and where kindred vibration may be felt.
Some of the lower devas, harmless but mischievous who, from sheer freakishness and fun, enter another body in much the same way that a child loves to dress up.
Occasional visitors from other planets who enter certain highly evolved bodies for purposes of their own. This is very, very rare... 
The Dark Brotherhood
September 25, 1919
Today I seek to speak to you on The powers of the Dark Brotherhood. Certain laws that govern their actions,  certain methods employed by them in work need to be realized and certain methods of protection apprehended and utilized. As before I have told you the danger is as yet inappreciable to the majority, but more and more as time elapses shall we find it necessary to teach you, the physical plane workers, how to shield and guard yourselves from attack.
The Dark Brothers are - remember this always - brothers, erring and misguided yet still sons of the one Father though straying far, very far, into the land of distances. The way back for them will be long, but the mercy of evolution inevitably forces them back along the path of return in cycles far ahead. Anyone who over-exalts the concrete mind and permits it continuously to shut out the higher, is in danger of straying on the left-hand path. Many so stray... but come back, and then in the future avoid like errors in the same way as a child once burnt avoids the fire. It is the man who persists in spite of warning and of pain who eventually becomes a brother of darkness. Mightily fights the Ego at first to prevent the Personality so developing, but the deficiencies of the causal body (for forget not that our vices are but our virtues misused) result in a lop-sided causal body, over-developed in some direction and full of great gulfs and gaps where virtues should be.
The dark brother recognizes no unity with his species, only seeing in them people to be exploited for the furtherance of his own ends. This then, on a small scale, is the mark of those who are being used by them wittingly or unwittingly. They respect no person, they regard all men as fair prey, they use everyone to get their own way enforced, and by fair means or foul they seek to break down all opposition and for the personal self acquire that which they desire. 
The dark brother considers not what suffering he may cause; he cares not what agony of mind he brings upon an opponent; he persists in his intention and desists not from the hurt of any man, woman or child, provided that in the process his own ends are furthered. Expect absolutely no mercy from those opposing the Brotherhood of Light.
On the physical plane and on the emotional plane, the dark brother has more power than the Brother of the Light, - not more power per se but more apparent power, because the White Brothers choose not to exert Their power on those two planes, as do the Dark Brothers. They could exert Their authority but They choose to refrain, working with the powers of evolution and not of involution. The elemental forces to be found on these two planes are manipulated by two factors.
The inherent forces of evolution that direct all on to eventual perfection. The White Adepts cooperate in this.
The Dark Brothers who occasionally employ these elemental forces to wreak their will and vengeance on all opponents. Under their control work sometimes the elementals of the earth plane, the gnomes and the elemental essence as found in evil form, some of the brownies, and the fairy folk of colors brown, gray and somber-hued. They cannot control the devas of high development, nor the fairies of colors blue, green and yellow, though a few of the red fairies can be made to work under their direction. The water elementals (though riot the sprites or sylphs) move on occasion to their assistance, and in the control of these forces of involution they at times damage the furtherance of our work. 
Oft too the Dark Brother masquerades as an agent of the light, oft he poses as a messenger of the gods, but for your assurance I would say that he who acts under the guidance of the Ego will have clear vision, and will escape deception.
At this time their power is oft-times mighty. Why? Because so much exists as yet in the Personalities of all men that respond to their vibration, and so it is easy for them to affect the bodies of men. So few of the races, comparatively speaking, have as yet built in the higher vibration that responds to the keynote of the Brotherhood of Light, who move practically entirely on the two highest levels (or the atomic and subatomic subplanes) of the mental, emotional and physical planes. When moving on these subplanes the attacks of elementals on lower planes may be felt but effect no harm, hence the necessity of pure living and controlled pure emotions and elevated thought.
You will notice that I said that the power of the Dark Brotherhood is dominant apparently on the physical and emotional planes. Not so is it on the mental, which is the plane on which the Brothers of the Light work. Mighty dark magicians may be located on the lower mental levels, but on the higher, the White Lodge dominates, the three higher subplanes being the levels that They beg the evolving sons of men to seek; it is Their region, to which all must strive and aspire. The Dark Brother impresses his will on human beings (if analogous vibration exists) and on the elemental kingdoms of involution. The Brothers of Light plead as pleaded the Man of Sorrows for an erring humanity to rise upward to the light. The Dark Brother retards progress and shapes all to his own ends; the Brother of Light bends every effort to the hastening  of evolution and - foregoing all that might be His as the price of achievement - stays amid the fogs, the strife, the evil and the hatred of the period if, in so doing, He may by all means aid some, and (lifting them up out of the darkness of earth) set their feet upon the Mount, and enable them to surmount the Cross.
And now what methods may be employed to safeguard the worker in the field of the world? What can be done to ensure his safety in the present strife and in the greater strife of the coming centuries?
A realization that purity of all the vehicles is the prime essential. If a Dark Brother gains control over any man it but shows that that man has in his life some weak spot. The door whereby entrance is effected must be opened by the man himself; the opening whereby malignant force can be poured in must be caused by the occupant of the vehicles. Therefore the need of scrupulous cleanliness of the physical body, of clean steady emotion permitted in the emotional body, and of purity of thought in the mental body. When this is so, coordination will be present in the lower vehicles and the indwelling Thinker himself permits no entrance.
The elimination of all fear. The forces of evolution vibrate more rapidly than those of involution and in this fact lies a recognizable security. Fear causes weakness; weakness causes a disintegration; the weak spot breaks and a gap appears, and through that gap evil force may enter. The factor of entrance is the fear of the man himself, who opens thus the door.
A standing firm and unmoved, no matter what occurs. Your feet may be bathed in the mud of earth, but your head may be bathed in the sunshine of the higher regions. Recognition of the filth of earth involves not contamination. 
A recognition of the use of common sense and the application of this common sense to the matter in hand. Sleep much and, in sleeping, learn to render the body positive; keep busy on the emotional plane and achieve the inner calm. Do naught to overtire the body physical, and play whenever possible. In hours of relaxation comes the adjustment that obviates later tension. 
Part of the Satan Myth by Henry T. Edge
As published in THE THEOSOPHICAL FORUM of April 1936; page. 264 to 268
The natural intelligence of man has felt that the truth must be one and single, not divided into two opposite species. A God that is all wise and all loving cannot rightly be conceived as an obscurantist. Then there is the well-known problem why such a God could create man, allow him to fall or be led by Satan into corruption, and then provide for his rescue by doubtful means and one that (in strict theological interpretation) comprehends but a minute fraction of the human race. Things like these have driven many worthy souls out of religion altogether, unaware that there was any genuine truth to replace the spurious article which they have rejected. This is what is meant when we say that the theological interpretation conflicts with human experience instead of explaining it. This divorce between two vital aspects of truth has also had a disastrous effect on science, causing it to propound a view of man's origin and nature based on purely physical influences. The duality of man's nature is the most common fact of experience, constituting as it does the entire motive of the drama of human life. It is surely the function of any body of doctrine, whether it pose as religious or scientific, to explain this fact of man's duality. If we compare the stories of man's creation as found in the various scriptures and mythologies, we find everywhere a dual creation of man. He is created as an innocent being, without knowledge of good and evil, without free choice, living in a state of harmless and unprogressive bliss. Afterwards he is enlightened by the gift of divine fire, which turns him into a responsible being, made in the image of his divine creators, and destined thenceforth to learn wisdom by experience of pain and pleasure, wrong and right. Such is the true interpretation of the allegory in Genesis.
The Serpent is man's real Savior. It is this Serpent that teaches man the knowledge of good and evil and makes him like unto the Gods. The Serpent is actually the Lord God in another form, perfecting his own original work and making of the earlier mindless man a complete being, a fitting image of his divine author. The Greeks tell the same thing in the story of Prometheus. He takes compassion on helpless mankind and brings fire down from heaven in a tube, enlightening men. There is the same apparent hostility between Zeus and Prometheus as between the Lord God and the Serpent. It is evident that the man of Eden, and the man whom Prometheus enlightened, were little better than automatons. Such a being could only become a real man by having a choice given him. Only thus could he exercise free will, that attribute of divinity. The exercise of free will and choice can be construed into an act of rebellion. Satan is said to have rebelled against God and fallen from heaven. He did so in compassion for man, performing an act of self-sacrifice for the salvation of man, just as Prometheus sacrificed himself and was ejected from Olympus to be fastened to a rock. Satan is the head of a host of angels, who with him rebelled against God and fell from heaven. They were the true enlighteners of man. This allegory of the Fallen Angels has been so misrepresented that it may seem as though we were being profane in so speaking of it. In fact, it is one of the most holy and sublime teachings of ancient wisdom.
The kind of evolution studied by science cannot produce anything higher than animals. The human self-conscious intelligence can never have been evolved from the animal mind. It is a gift apart. This gift of the divine intelligence is passed on from beings that have it to those who come after them. It is brought to men from above, not worked up from below. The scriptures say that in ages long gone by, man walked with the Gods. Man had intercourse with divine beings. It was thus that man received that marvelous intelligence which, all obscured as it is by his mortal clay, yet makes him so immeasurably above the animals. The earliest races of mankind were mindless, sinless, and devoid of initiative. Later in evolution, the divine fire was passed to man from beings who had acquired it before. Man was enlightened. This teaching regarding the evolution of human races is too long to be entered into here, but can be found in Theosophical books. It is allegorized in the Bible and other sacred books. The temptation of flesh in the Garden of Eden is a gross misinterpretation of the allegory. God has been represented as cursing forever what was a purely natural act and function. Here is another false antithesis, by which natural functions have been connected with the idea of sin. Man has been set at war with himself.
Endless moral confusion has gone down through the ages. If this Biblical Satan is a name for man's enlightener, and not the archfiend and enemy of God and man, nevertheless there may be a real devil among us. This devil is our own personified passions and evil thoughts. We know this devil by experience. We know how the alliance between fleshly passion and human self-consciousness can engender an evil personality that steps into our clothes and wears our mask. It is not mere physical immorality, harmful though that may be, that is the worst foe of man. It is selfishness, hate, anger, cruelty, and heartlessness. These whither and petrify the soul. It is riot those who have been most noted for sanctimoniousness who have been most free from this kind of sin. Man's true redeemer is that Divine Spirit which was breathed into him when from being an unselfconscious creature he became like unto the Gods. For man, good is what expands and evil is what contracts. Good sets the common weal above so-called personal interest. Evil seeks to promote self-interest regardless of the common weal. Good is constructive and makes for harmony. Evil is destructive and makes for discord. Equally fatuous are both those who accept the Eden story in its literal sense and those who scoff at it as foolish superstition. They both make the same mistake. They are guilty of the same lack of proportion. The story is symbolic and allegorical. The same symbols are universally found.
What is that Tree of the Knowledge of Good and Evil, that Tree of Life, that pleasure garden? The Garden is the state of primitive innocence in which dwelt early man, when yet the light from Heaven had not kindled the latent spark within him. The Tree, Tau, and Cross are universal symbols of the Wisdom-Religion, as is the fruit which hangs near the top of the Tree. Around the Tree, we often find a Serpent coiled -- the universal emblem of Wisdom. ("Be ye wise as serpents.") This is the origin of the Christian Cross, which should symbolize the sacrifice of self for Self, the salvation of man by exchanging the mortal for the immortal, the true Resurrection from the dead. These most sacred symbols have been turned into a dogmatic system, in which man is made to believe himself doomed by the sin of Adam to eternal damnation, only to be saved by an act of homage to a crucified God. See how good and evil have been mixed up, that which is holy profaned, and man made to damn his own God-given faculties. The above is not an advocacy of anything like Satanism or devil worship, or any such evil cult as may be found lurking in dark corners today. The distinction between good and evil is clear enough. If Satanism means the deification of evil passions, black magic, and sorcery then the name of the divine archangel has again been traduced. Such unhallowed cults are simply one of the natural results of denying man his own natural power of self-directed evolution. By cutting him off from the true light, we drive him to seek refuge in false lights. The Bible is one of the world's sacred scriptures. When we know the keys, we can interpret it aright. It can also be interpreted entirely wrong, so that a fraud has been practiced on humanity.
Next: Evil studied from different angles part 2 with notes from different esoteric scholars about The Dweller on the Treshold and a view of Ann Davis on Tarotcard 15.(The Devil).