|Chapter 3: Karma-yoga|
na hi kascit kshanam api
jatu tishthaty akarma-krit
karyate hy avasah karma
sarvah prakriti-jair gunaih
Everyone is forced to act helplessly according to the qualities he has acquired from the modes of material nature; therefore no one can refrain from doing something, not even for a moment.
Srila Prabhupada explains in his purport: "It is not a question of embodied life, but it is the nature of the soul to be always active. Without the presence of the spirit soul, the material body cannot move. As such, the spirit soul has to be engaged in the good work of Krishna consciousness; otherwise, it will be engaged in occupations dictated by illusory energy."
In Chapter Two, Krishna told Arjuna, "karmanya eva adhikaras te: your eligibility (adhikara) on the yoga ladder is not renunciation of work but action. Because the soul must act, the Vedas prescribe duties to purify the living entities. Thus by acting according to sastra, in a detached mood, in knowledge of the difference between the self (the eternal soul) and the body (matter), one becomes elevated to the gyana platform. Only then does one have the option to give up prescribed duties and take sannyasa.
Please read the Sanskrit Verse and the Prabhupada's Purport.