Bhagavad Gita Chapter 2 Sloka 20 (2.20)

ನ ಜಾಯತೇ ಮ್ರಿಯತೇ ವಾ ಕದಾಚಿತ್ ನಾ[S]ಯಂ ಭೂತ್ವಾ ಭವಿತಾ ವಾ ನ ಭೂಯಃ ।
ಅಜೋ ನಿತ್ಯಃ ಶಾಶ್ವತೋSಯಂ ಪುರಾಣೋ ನ ಹನ್ಯತೇ ಹನ್ಯಮಾನೇ ಶರೀರೇ ॥೨೦॥
na jāyate mriyate vā kadācit nā[S]yaṃ bhūtvā bhavitā vā na bhūyaḥ |
ajo nityaḥ śāśvatoSyaṃ purāṇo na hanyate hanyamāne śarīre ||20||
Gist of the sloka:
This soul has no birth, death or changes. The soul is the reflection of the Lord, who has no birth, death nor change. Same with the soul. Soul which migrates from body to body, will not die even when the body dies.
Explanation:
Lord Krishna is explaining about the jeeva-swaroopa. This jeeva-swaroopa does not have birth, death nor does it changes or destroyed. It remains always in a steady state. The reaon being the individual soul is a reflection of the supreme Lord. Lord has no birth, death nor does He change. Being the reflection of such a Lord, individual soul also behaves in similar manner. Even when the body changes from birth to birth the soul and its swabhava never changes. The gross body does age but not the soul. Its behavious or qualities due to the influence of the 3 gunas and prabhava might change but its swabhavana never changes. A soul in one life might be a atheist and in the next might be a believer.