You must remember that you will meet with those individuals who are themselves the bearers of antagonistic forces, instruments of darkness--sometimes consciously, mostly unconsciously, people used by evil forces. So far as possible you must avoid such people. Certainly never enter into intimate association with them, whether the relation be business or personal. If you do you will find that sooner or later some of their unfortunate karma will tumble on you and you will have to suffer with them. These people are opposed to your quest and all that it stands for, although they may talk as believers in spiritual things--indeed, they often belong to some cult or other. But they do not understand truth or live it. They cannot help you and you are not strong enough to carry them. So leave them alone. And that is not always easy, because often they are people of a kind that force themselves into your life. Sometimes you can know them by this hallmark, by this aggressive way which they try to entangle you. It may even be necessary at times to deal with such people with a firm hand, even mercilessly and relentlessly. If so, do not hesitate, but do it without any personal feeling of any kind.
-- Notebooks Category 11: The Negatives > Chapter 4: In Thoughts, Feelings, Violent Passions > # 120