Bhagavad Gita

ಅವ್ಯಕ್ತೋSಯಮಚಿಂತ್ಯೋSಯಮವಿಕಾರ್ಯೋSಯಮುಚ್ಯತೇ ।
ತಸ್ಮಾದೇವಂ ವಿದಿತ್ವೈನಂ ನಾನುಶೋಚಿತುಮರ್ಹಸಿ ॥೨೫॥
avyaktoSyamaciṃtyoSyamavikāryoSyamucyate |
tasmādevaṃ viditvainaṃ nānuśocitumarhasi ||25||

Gist of the sloka:
The Vedas says that Lord is never changing, not visible and difficult to understand. Once you understand this fact, lamenting is not appropriate.
Lord is not visible and neither does the soul within the gross body. Due to which its very difficult to understand the nature of Lord and the soul. We do not know where we came from? Who are we?
The nature of Lord and soul is unchanging also. All this is beyond our normal thinking. Once we understand the truth about the nature of Lord and soul, to lament about the death is meaningless.
All mention of soul [Atma] refers to individual souls [not Lord’s] unless otherwise mentioned.