The body is the root substance. The soul is animate. It is Aj, Ajar and Amar, that is, constant and indestructible. It is also written in the Gita that 'it can not cut the weapon, the fire can not burn, the water can not swallow, the air can not dry.' The light which is in you, which is the soul, never dies. Death does not cling to it, that means death can not touch you either.
We should not forget that the second meaning of death is also 'new birth'.