The spirit is indestructible. Disease, death, suffering, cannot destroy it. It follows the rule that ‘energy cannot be created nor destroyed, it can , however be converted from one from to another’.So the Geeta says that life and death is cyclical. This cycle does not destroy the spirit or Atma.
So the spirit is one with the universal energy, which we may call ‘God’.
Thoughts, emotions, are part of the mind, are is a constant state of movement and change. If one can realize that the spirit is not the same as the mind, he may well change the way he lives.