Simply working is not karma-yoga. Karma-yoga means... It is described in the Bhagavad-gita, yat karoсi [Bg. 9.27]. Whatever you are doing. Yat karosi yaj juhosi. Whatever you are sacrificing. Yad asnasi, whatever you are eating. Yad dadasi, whatever you are giving in charity. Kurusva tad mad-arpanam, "give Me." "You want to give some charity, give Me," Krsna says. But people will not give Krsna. If the members of the Krsna consciousness goes to some foundation, that "We are being doing this work. Give us some money." "No. Our money is meant for hospital and educational institution." And what you are producing? "Atom bomb. Oh, that is all right." This is going on. So we are, by material advancement, we are just advancing the cause of illusion. That is all.
Lecture on Bhagavad-gita 6.40-42, New York, 16 September, 1966