Like heat and light are the attributes for fire, projection and veiling are the attributes of Consciousness/चेतना or Brahman.
Projection projects this physical universe including, our bodies, mind, and things around us, and for that matter, planets, galaxies, and everything around it.
Just as heat and light depend on fire for their existence, the projected universe depends on Consciousness/चेतना for its existence. That is the reason the universe is असत्, and Brahman alone is सत्.
Therefore, if we tear up the layers of names and forms, we will find that everything everywhere is just Brahman. They are just different names given to the various forms of the Brahman.
There is only one अद्वितीय, अद्वैत Brahman. Most importantly, this Brahman is NONE OTHER than we, ourselves.
There is no beginning or end to Brahman. Brahman is everlasting. It was there before this universe got projected, and will be there even after the universe is destroyed, just to restart the next cycle. Brahman’s existence doesn’t depend on anything else, so it is indestructible.
To summarize this discussion, Shri Krishna says in the next Shloka:
अविनाशि तु तद्विद्धि येन सर्वमिदं ततम् |
विनाशमव्ययस्यास्य न कश्चित्कर्तुमर्हति ||2.17||
That which pervades everything, know it to be indestructible. No one can destroy that imperishable Brahman (सत्, or Consciousness/चेतना).
While Brahman is indestructible, the projection that emits from it is ever-changing.
Within the projection, i.e. in this material universe or प्रकृति, nature’s laws become applicable. Along with various laws of physical entities, at the level of Suksham and Karan Sharir, the laws of Karma also apply.
As Brahman, these laws don’t apply to us, but they apply to the bodies and Suksham/Karan Sharir we have got. Similarly, as Brahman, we have no prescribed duties, but this body and Suksham/Karan have their assigned duties. So, we have to let them do their jobs without getting disturbed by them.
Trouble starts when we identify ourselves with the body and start owing its Karma, duties, responsibilities. This is the reason we “appear” to be stuck in the cycle of life and death.
As you can see, I have used the phrase “appear to be stuck”, that’s because, as Brahman, there is no birth or death for us. We are always free.
At this very moment, we are free. We just appear to be stuck as we are owning up to something that is not ours. The moment we realize this and understand our true nature, this appearance will also disappear.
Anyways, coming back to the story, Arjun’s body is born with क्षत्रिय Guna. So, he must let his body follow nature’s laws and fight.
That’s what Shri Krishna tries to explain to Arjun:
अन्तवन्त इमे देहा नित्यस्योक्ता: शरीरिण: |
अनाशिनोऽप्रमेयस्य तस्माद्युध्यस्व भारत ||2.18||
Only the material body is perishable. The one that pervades this body is indestructible, immeasurable, and eternal. Therefore, O’ Arjun, you must fight.