Have you ever wondered about this question?  One of the great unanswered questions of all time.  I've wondered about this often!!  My personal take on this is that though life ceases to exist (as we know it) - perhaps people and living beings live on, perhaps in a different state. That different state most likely being energy.  One may call it the soul!  To me it seems like the 'soul' and energy are one and the same!!  But, whatever, I think living beings just don't disappear into nothingness.  That would seem illogical.  How can something that has mass disappear and become nothingness?  I've read up on some theories that seek to explain death and what happens after death.  In that respect, the reincarnation theory interests me. It seems to make sense to me. Everything in nature is cyclical, isn't it?  So, why not creation and destruction of life.

You have creation, destruction and then creation again. Death just destroys the mass (matter).  That equivalent mass/matter is converted into other forms - like energy.  Death, I believe, is just a transformation.  It just frees up the energy (soul) from the physical body it is trapped in.  That energy could be called the soul.  Perhaps, the soul then seeks out a new able body, one which is not damaged or worn out and one which can sustain itself and begin the cycle again - the cycle of birth and death!!  Seems plausible to me.

How do we define death after all?  Does death occur when the heart stops beating?  Are we 'alive' solely because our heart beats or because of our various bodily functions?  Isn't the 'alive' part due to something undefinable - call it consciousness or the 'soul' or 'energy.'