The body means the senses. That means anything which we do for sense gratification, that is material. And anything which we do for the satisfaction of the Supreme, that is spiritual platform. That's all. So we have to discriminate "Whether I am working for sense gratification or whether I am working for the satisfaction of the Supreme?" If this art we can learn, then our life becomes spiritualized. Spiritual life does not mean that we have to change something of these activities which we are, already we are engaged, or our form of the body will change to something extraordinary. Nothing. The same body, the same feature, the same activity, same engagement - everything same. But we have to know the art, "Whether these activities are being done from the spiritual platform or from the material platform?"
Lecture on Bhagavad-gita 2.49-51, New York, 5 April, 1966