Bhagavad Gita

ಅಂತವಂತ ಇಮೇ ದೇಹಾ ನಿತ್ಯಸ್ಯೋಕ್ತಾಃ ಶರೀರಿಣಃ ।
ಅನಾಶಿನೋSಪ್ರಮೇಯಸ್ಯ ತಸ್ಮಾದ್ ಯುಧ್ಯಸ್ವ ಭಾರತ ॥೧೮॥
aṃtavaṃta ime dehā nityasyoktāḥ śarīriṇaḥ |
anāśinoSprameyasya tasmād yudhyasva bhārata ||18||

Gist of the sloka:
The immortal soul is in this mortal body. He has no destruction. He is the reflection of the omnipresent Lord. O Bharatha, in the name of this imperishable Lord, fight.
The gross body is perishable. Soul which is in it is not. From the eyes of this gross body, we can only view the gross world. This soul is reflection of the omnipresent indestructible Lord and hence the Soul also does not perish.
Lord Krishna guides Arjuna by indicating to him, that Arjuna should fight the war not with the intention of obtaining the kingdom nor for the cause of Duryodhana; but with the intention that this task of fighting the war is but a form of worship to the universal Lord.
We too should perform our everyday tasks in the similar form. This body was given to us by the Lord and it belongs to Him alone. We are but temporary residents given an opportunity to use this body to worship the Lord and obtain his grace.
With his mindset, we should offer our services to Him alone. When this body collapses, we should not get disturbed as it was given to us for a certain time and purpose and it has been taken back. Grief regarding this would be unnecessary.