Bhagavad Gita: Chapter 14, Verse 14-15

यदा सत्त्वे प्रवृद्धे तु प्रलयं याति देहभृत् |
तदोत्तमविदां लोकानमलान्प्रतिपद्यते || 14||
रजसि प्रलयं गत्वा कर्मसङ्गिषु जायते |
तथा प्रलीनस्तमसि मूढयोनिषु जायते || 15||

yadā sattve pravṛiddhe tu pralayaṁ yāti deha-bhṛit
tadottama-vidāṁ lokān amalān pratipadyate
rajasi pralayaṁ gatvā karma-saṅgiṣhu jāyate
tathā pralīnas tamasi mūḍha-yoniṣhu jāyate

yadāwhen; sattvein the mode of goodness; pravṛiddhewhen premodinates; tuindeed; pralayamdeath; yātireach; deha-bhṛitthe embodied; tadāthen; uttama-vidāmof the learned; lokānabodes; amalānpure; pratipadyateattains; rajasiin the mode of passion; pralayamdeath; gatvāattaining; karma-saṅgiṣhuamong people driven by work; jāyateare born; tathālikewise; pralīnaḥdying; tamasiin the mode of ignorance; mūḍha-yoniṣhuin the animal kingdom; jāyatetakes birth

yada sattve pravriddhe tu pralayam yati deha-bhrit
tadottama-vidam lokan amalan pratipadyate
rajasi pralayam gatva karma-sangishu jayate
tatha pralinas tamasi mudha-yonishu jayate

Translation

BG 14.14-15: Those who die with predominance of sattva reach the pure abodes (which are free from rajas and tamas) of the learned. Those who die with prevalence of the mode of passion are born among people driven by work, while those dying in the mode of ignorance take birth in the animal kingdom.

Commentary

Shree Krishna explains that the destiny awaiting the souls is based upon the guṇas of their personalities. We get what we deserve is God’s law, the law of karma. Those who cultivated virtues, knowledge, and a service attitude toward others are born in families of pious people, scholars, social workers, etc. Or else, they go to the higher celestial abodes. Those who permitted themselves to be overcome by greed, avarice, and worldly ambitions are born in families focused on intense material activity, very often the business class. Those who were inclined to intoxication, violence, laziness, and dereliction of duty are born amongst families of drunks and illiterate people. Otherwise, they are made to descend down the evolutionary ladder and are born into the animal species.

Many people wonder whether having once attained the human form, it is possible to slip back into the lower species. This verse reveals that the human form does not remain permanently reserved for the soul. Those who do not put it to good use are subject to the terrible danger of moving downward into the animal forms again. Thus, all the paths are open at all times. The soul can climb upward in its spiritual evolution, remain at the same level, or even slide down, based upon the intensity and frequency of the guṇas it adopts.