Consider alike pleasure and painSukha Duhkhe Same Krithva Labhalabhou Jayajayau
Tato Yuddhaya Yujyasva Naivam Papamavapsyasi
In this verse, Sri Krishna begins with his discourse on Karma Yoga which is the essence of the Bhagavad Gita. Meditation is not about renunciation of action, but on how to renounce the results by being in the thick of action. Anhd so Sri Krishna tells Arjuna to consider alike joy and sorrow, benefits and losses, victory and defeat. With this attitude, please get ready to fight in this war. If you fight in this manner you will not incur any sin, he tells Arjuna.
Sin is nothing but a restless state of mind that is born out of doing an action. Whatever the action may be, if the doer performs it in a sense of duty, rather than letting the mind get lost in whether it will incur sin or not - then such an action will not disturb his peace of mind. - Swahilya Shambhavi.