Bhagavad Gita
2.17

अविनाशि तु तद्विद्धि येन सर्वमिदं ततम् | विनाशमव्ययस्यास्य न कश्चित्कर्तुमर्हति ||१७||

avināśhi tu tad viddhi yena sarvam idaṁ tatam vināśham avyayasyāsya na kaśhchit kartum arhati

Translation

Know that to be indestructible by which this entire universe is pervaded. No one can cause the destruction of the imperishable soul.

Interpretation

The soul pervades all of existence — it is not confined to one body but is the very fabric of consciousness through which the universe is experienced. 'Avināśhi' — indestructible. No weapon, no fire, no element can destroy it. This is not a belief but an ontological fact that can be verified through deep self-inquiry.