One should not endeavor for ugra-karma, or unnecessary work for sense gratification. Nunam pramattah kurute vikarma yad indriya-pritaya aprnoti (SB 5.5.4). Simply for sense gratification, people make plans for material happiness. Maya-sukhaya bharam udvahato vimudhan (SB 7.9.43). They do this because they are all vimudhas, rascals. For flickering happiness, people waste their human energy, not understanding the importance of the Krsna consciousness movement but instead accusing the simple devotees of brainwashing. Demons may falsely accuse the preachers of the Krsna consciousness movement, but Krsna will arrange a fight between the demons in which all their military power will be engaged and both parties of demons will be annihilated.

Srila Prabhupada, SB 9.24.59, Purport