Alice A. Bailey (AAB) and Djwhal Khul (DK) writing on planetary evil imply that evil is a necessary part of Creation as Spirit is projected into matter. They also distinguish between planetary evil and cosmic evil.
Below are some quotes from the writings of AAB and DK on the subject of evil, particularly planetary evil.
First. It should be remembered that the whole subject of planetary evil (and students must distinguish carefully between planetary and cosmic evil) lies hid in the individual life cycles and in the history of the Great Being who is the planetary Logos of the Earth. Therefore, until a man has taken certain initiations and thus achieved a measure of planetary consciousness, it is useless for him to speculate upon that record. H. P. B. has touched, in the Secret Doctrine [S. D., III, 62; Section 6, page 67] , upon the subject of “the imperfect Gods,” and in these words lies the key to planetary evil.
Second. It might briefly be said that, as far as our humanity is concerned, the terms planetary evil and cosmic evil might be interpreted thus:
Planetary evil arises from certain relations existing between our planetary Logos and another planetary Logos. When this condition of polar opposition is adjusted, then planetary evil will cease. The adjustment will be brought about through the mediation (occultly understood) of a third planetary Logos. These three will eventually form an equilateral triangle, and then planetary evil will cease. Free circulation will ensue; planetary obscuration will become possible, and the “imperfect Gods” will have achieved a relative perfection. Thus will the karma of the manvantara, or secondary cycle, be adjusted, and so much planetary karmic evil be “worked off.” All the above must be interpreted in its esoteric sense and not its exoteric.
The task ahead of humanity is to close the door upon this worst and yet secondary evil and shut it in its own place. There is enough for humanity to do in transmuting planetary evil without undertaking to battle with that which the Masters Themselves can only keep at bay, but cannot conquer. The handling of this type of evil and its dissipation, and therefore the release of our planet from its danger, is the destined task of Those Who work and live in “the centre where the Will of God is known,” at Shamballa; it is not the task of the Hierarchy or of humanity. Remember this, but remember also that what man has loosed he can aid to imprison; this he can do by fostering right human relations, by spreading the news of the approach of the spiritual Hierarchy, and by preparing for the reappearance of the Christ. Forget not also, the Christ is a Member of the Great Council at Shamballa and brings the highest spiritual energy with Him. Humanity can also cease treading the path to the “door where evil dwells” and can remove itself and seek the Path which leads to light and to the Door of Initiation.