You believe you are so good, so kind, so well disposed and always full of good feelings. You wish no harm to anybody, you wish only good—all that you tell yourself complacently. But if you look at yourself sincerely as you are thinking, you notice that you have in your head a collection of thoughts which are sometimes frightful and of which you were not at all aware.
For example, your reactions when something has not pleased you: how eager you are to send your friends, relatives, acquaintances, everyone, to the devil! How you wish them all kinds of unpleasant things, without even being aware of it! And how you say, “Ah, that will teach him to be like that!” And when you criticise, you say, “He must be made aware of his faults.” And when someone has not acted according to your ideas, you say, “He will be punished for it!” and so on.
You do not know it because you do not look at yourself in the act of thinking. Sometimes you know it, when it becomes a little too strong. But when the thing simply passes through, you hardly notice it—it comes, it enters, it leaves. Then you find out that if you truly want to be pure and wholly on the side of the Truth, then that requires a vigilance, a sincerity, a self-observation, a self-control which are not common. You begin to realise that it is difficult to be truly sincere.
You flatter yourself that you have nothing but good feelings and good intentions and that whatever you do, you do for the sake of what is good—yes, so long as you are conscious and have control, but the moment you are not very attentive, all kinds of things happen within you of which you are not at all conscious and which are not very pretty.
Ref : Question and Answers 1929-1931