The Bhagavad Gita

कर्मण्येवाधिकारस्ते मा फलेषु कदाचन । मा कर्मफलहेतुर्भुर्मा ते संगोऽस्त्वकर्मणि ॥

कर्म करना तो तुम्हारा अधिकार है, लेकिन उसके फल पर कभी नहीं| कर्म को फल की इच्छा से कभी मत करो, तथा तेरा कर्म ना करने में भी कोई आसक्ति न हो|

The Bhagavad Gita is a collection of scriptures that contain the spiritual discourse given by Lord Krishna to Arjuna just before he is to commence battle. Krishna convinces Arjuna to fight the righteous war or the Dharma Yuddha between the Kauravas and the Pandavas. He is appealing to him to fulfill his righteous duties as a Kshatriya and fight for the truth and what is right.

Arjun was not willing to fight, given that he had in the opposing camp, all those persons he considers to be his own. Arjun says to Krishna, what’s the use of fighting against my own for just a piece of land. What happiness will I get by slaying my dear ones? The ones on the other sides are my own uncle, my cousin. Won’t I be committing a sin? What will I get by killing all of them.

Krishna tells Arjun that no matter what the result of the war is, he should not be worried about it. His duty is to fight, then he has to fight. He wins or loses that is not important. Even if he dies during the war, he will attain heaven because he has correctly performed his duty.

Karmanye Vadhikaraste, Ma phaleshou kada chana - You have the right to perform your actions, but you are not entitled to the fruits of the actions. 

Ma Karma Phala Hetur Bhurmatey Sangostva Akarmani – Do not let the fruit be the purpose of your actions, and therefore you won’t be attached to not doing your duty.

“The meaning of Karma is in the intention. The intention behind the action is what matters. Those who are motivated only by the desire for the fruits of action are miserable, for they are constantly anxious about the results of what they do.”