When Krishna asks Arjuna to fight the Mahabharat war then Arjuna is perturbed. He thinks that Krishna has explained that I am not this body but a soul. And as a soul I am spiritual and eternally related to Krishna. This body and all the relationships pertaining to this body is temporary.
So, why does Krishna want me to engage in any activity in this material world? Even if I win the war then what is the gain? Because ultimately, I will have to leave this body, so why to waste my time in this mundane affair?
Arjuna said: O Janārdana, O Keśava, why do You want to engage me in this ghastly warfare, if You think that intelligence is better than fruitive work? Bhagavad Gita 3.1
This question confused Arjuna at the battlefield of Kurukshetra and this also confuses devotees who begin practicing Krishna Consciousness.
Like Arjuna we get confused about our prescribed duties
I remember in my college days when I got introduced to Krishna Consciousness then I also had the same question. Why should I study? What is the purpose of study? What is the benefit of getting good marks? And when I spoke to other devotee friends studying with me, they too had the same thoughts.
Before coming to Krishna consciousness, we want to work hard for success and for name and fame. But when we come to Krishna Consciousness, we start understanding how futile is mundane desire. Because nothing material is sustainable and most importantly, it never gives any pleasure to the soul.
So, we start thinking that better to refrain from all material duties. The same thought Arjuna had. Why to fight the Mahabharat war?
Never give up your prescribed duties
But Arjuna was fortunate that he had with him Krishna. And Krishna explained to Arjuna that the purpose of human life is to cleanse the heart of all the impurities and return back to the spiritual world. With impure heart we won’t attain the desired destination. Cleaning heart of all the dirt becomes easy when we engage in our prescribed duties. So, Krishna asks Arjuna to not give up his prescribed duty of fighting.
Arjuna was a kshatriya and so his duty was to fight the Mahabharat war to establish dharma. Similarly, we also have our prescribed duties as a student, as a working professional, as a housewife. So, we should not run away from our responsibilities.
But it does not mean that we should only be engaged in our prescribed duties. It is important that while doing our duty we should constantly remember Krishna. Because if we do so then we will always be in Krishna Consciousness.
How to work in this world?
Externally what we are doing and what the materialists are doing may look the same. But internally there will be an ocean of difference.
For example, Arjuna was fighting and also Duryodhana was fighting but Arjuna was fighting by keeping Krishna in the centre and Duryodhana was fighting for his selfish desire. So, we should follow the footsteps of Arjuna and not of Duryodhana.
If we do so, then like Arjuna we will also be victorious in our life. And Krishna will be pleased with us. Also, by doing our duty by keeping Krishna in our heart, our heart will get cleansed of all the impurities. Once our heart becomes pure, we will attain perfection and become eligible to return back to the kingdom of Krishna.