consciousness (atman/soul) is self-existent, ever-blissful non-material energy. it has no beginning and no end. It never born so never dies. it's the absolute truth because it's not subjected to change, death and decay. Material reality is only a relative truth because it's always changing. Whole of our body cells recycle every year. But we're still aware of the body as before. that awareness is the non-material atman, which associates, itself with this body as long as it's bound.
Yogis for ages have been able to go to the source – atman – by silenting the mind and its modifications (vritis) and have been able to observe the causal, subtle and gross planes of existence along with wheel of time. Hence Upanishad declares: "That which cannot be observed through mind rather through which mind gets the ability to observe is atman"