The actions we see in this world, everything that happens around us is the manifestation of the thoughts of human being. It is the out come of will.
The third chapter of bhagavad geeta talks about Karma Yoga. It says that any creature cannot be without doing any action at any time. Everything we do is action and has a result. We have five sense organs and we do all our actions through these five senses directed by mind. The man who does actions without attachment to the fruits of the work is superior. Man has to work. Work is better than doing nothing. Even bodily maintenance is possible by means of work. A Karma Yogi does work and such work will never hurt any one. He sacrifices all his work to the supreme almighty. When the person is not attached to the fruits of the work, he will come out of the chain of pleasure and misery. Beyond that he will find joy.
People, giving more importance to ego, thinking - " I am the doer" get entangled in the net of fruits of action. Doing action only for pleasure might give pleasure or misery when the expected result does not come. But when a person does work without expectation and sacrificing the results to the supreme lord, he experiences Joy and bliss which is incomparable to little pleasures.
Some work to get fame, some for money, some for power and some for the purpose of going to heaven. But one has to work for the sake of work only. People wait to get to a destination - Result. But if one understands that the work itself is the destination, then the work will also be done better and there wont be any misery arising out of it.
Desire and Lust spoil a person completely. Like fire covered by smoke, Mirror covered by dust - True knowledge of self is covered by Lust and Ego. When one wipes of dust of lust and ego, one finds the true self and true knowledge.
Thoughts become actions. Bhagavad geeta says -
When one thinks too much about something with desire, attachment arises, attachment gives rise to lust, and when one does not get that thing the lust turns into anger, anger turns into psychological disorder and makes the person evil, the person causes harm to the society and self.
Surrendering all the work to the supreme almighty, gives you detachment, detachment gives strength to mind, it opens up the heart to the world, love for all the creatures arises in the heart, thereby one does good things that help others. One thinks good things and wishes good things to world.
Work for the sake of perfection, for the sake of work surrendering the result to the GOD. Is what bhagavad geeta says about Karma Yoga.