On the Karma Yoga of Gita

Every human being, each one of us, it born in human form to play a specific role, transacts some specific duty. This duty and one's ability to fulfill it depends upon one's intrinsic character since birth. Honest efforts to do the Karmas towards these duties are what could be termed as the gist of Karma Yoga. It was essentially this duty that Arjun was reminded by Lord Krishna in the holy Bhagvad Gita. Lord Krishna made him aware of the majestic purpose for which Arjun was born on the earth. God has given us the freedom of Karma and hence of creating our own future destiny; but we can't escape transacting the destined duties. God lives within every living being and triggers the direction of one's life as per the accumulated effects of one's past Karmas. The molecular or cellular components or the RBCs in our blood are bound to be at the assigned positions and be engaged in specific functions as per their biological nature. They are the parts of our body and hence should be governed by us. But we can't change their natural properties in any case. Thus, they are independent too … This is how we are also independent in God's creation.
We have the freedom in choosing our (new) karmas despite having to live as per certain destined circumstances, but the results of these would be according to our intentions, aim and nature of our Karmas as per the absolute law of the Supreme Creator. That is why God says - "Karmanyeva Adhikarste, Ma Phalesu Kadachan". Those who do not, and always expect desired outputs in return of their actions, are on the contrary, often found complaining their destiny or the world and remain desperate and dismayed most of the time.

Renunciation of Karma is Self- Deception
Often people misinterpret the preaching of the holy Gita and Vadanta and regard the state of inaction as that of detachment and soul-realization. But this is mere delusion, idleness and escapism. Making the body inactive or renouncing the family and duties does not serve any purpose of spiritual ascent. What is important is the liberation of the mind from all ego, expectations and selfish attachments. You should perform all your duties, do all your work at your level best but be detached from the end-result.
Don't expect the results of your actions to be as per your will or imagination. But don't leave your actions (Karmas) thinking that every thing will happen as per your destiny. You can't live even for a single moment without any Karma - be that physical or mental. You are born do transact your duties. This is what is implied in the following hymn:
"Na Kaschitksanamapi jatu
Tisthtykarma krat !
Karyate Hyavasah Karma Sarvah
Prakratijairgunaih !!"
The system of nature is such that it triggers every being, every particle, to act as per its natural tendencies. We might prevent the actions of our body or the sense organs for sometime; but what about the flow of thoughts and the impulses of unconscious mind? Those who attempt such superficial renouncement and try to evade from duties, actions suffer more agility and turbulence of desires and intrinsic tendencies in the mind … They are fame and self-cheaters.