Bhagavad Gita

ನಾಸತೋ ವಿದ್ಯತೇ [S]ಭಾವೋ ನಾಭಾವೋ ವಿದ್ಯತೇ ಸತಃ ।
ಉಭಯೋರಪಿ ದೃಷ್ಟೋSನ್ತಸ್ತ್ವನಯೋಸ್ತತ್ತ್ವದರ್ಶಿಭಿಃ ॥೧೬॥
nāsato vidyate [S]bhāvo nābhāvo vidyate sataḥ |
ubhayorapi dṛṣṭoSntastvanayostattvadarśibhiḥ ||16||

Gist of the sloka:
Neither the Lord nor Prakruthi has end. One does not get good rewards by doing bad things and one does not get bad things by doing good things. One who understands this truth has seen.
Lord Krishna is clearly indicating that doing good deeds one does not suffer. The reasoning behind is to assure Arjuna that during war in case he has to kill seniors than he should remember that he is fighting for the righteousness and should not fear going to hell or suffer from sins.
One should therefore should not fear doing good deeds and those who go in the part of evil will never get permanent happiness. It might appear that they [evil] might have trumped but it would be short term and they would fall into hell subsequently. This is the real ultimate truth that various rishi’s have discovered.
The verse can also be interpreted as follows. Neither prakruthi [Lakshmi] nor purusha [Lord] are ever nonexistent. They are ever present. So is the case of the soul who is dependent upon them. As such, this gross body made up of the 5 primary elements [earth, water, fire, air and openness(sky)] is a temporary place of stay and one should not feel excessively attached to it.