Two things must be completely avoided during occult training. We should never harm anyone through deeds, thoughts or words intentionally or not. Secondly, the feeling of hate must disappear in us, otherwise it reappears as a feeling of fear; for fear is suppressed hate. We must transform the hate into a feeling of love, the love of wisdom.
Source: Rudolf Steiner – GA 266 – From the Contents of Esoteric Classes – Kassel, 26th February 1909