This second mantra of the yogic scripture Sri Ishopanishad refers to karma yoga, or devotional service:

A person may desire to live for hundreds of years if he works according to this truth because that sort of work will not bind him to the law of karma. And there is no alternative to this way for man.
~Sri Ishopanishad, Mantra Two

~ Jagad Guru Chris Butler (Siddhaswarupananda Paramahamsa)

Everyone is engaged in action. The law of karma means that there are reactions to every action and that a person must endure the reactions to his actions.