I have been considering the idea of the human soul.  Most of my life I’ve been told things that now only make sense because I’ve been told them so often.  One amongst these silly things is that the soul lives on after the death of the body and goes either to an eternal reward or an eternal punishment.  Which part of this is the silly part?  
Let’s look at the world around us.  Look at the cycles of the tides, seasons, the moon, day and night.  Every autumn the leaves fall from the trees, they biodegrade amongst the dead animals and bio-waste products.  Biodegrade means to be eaten by bacteria and fungus, etc.  These things in turn fertilize new plants, which feed new animals, which feed even more animals, who all poop.  All this adds up to fertilized soil, healthy plants living in the deceased body parts of hundreds of other things in their biosphere.  
Seems to me the most natural thing in the world to have something cycle ‘round.  Why would a supreme creator produce all of this, create everything to work in cycles, constantly changing and refreshing, and then have a single part of one of its creations riven from it upon its physical death and placed, essentially, in a box for the rest of eternity?  Given close observation of the rest of our physical world, doesn’t it make more sense to believe that there are no eternal rewards or punishments?  If not, then what?
Another thing that occurs to me to question is the nature of the soul itself.  I was taught that it is a separate part that comes away after death.  Almost like the driver of a car who stops driving and gets out when he gets home.  Does this make sense?  Why would a god, any god, see some animal going about its business and decide to make some other part, an invisible part, to piggy back on it?  One thing I question is whether the soul is an integral part that makes a person whole, or if it may be a spiritually symbiotic part; similar to mitochondria in our cells that were once differentiated bacteria.
If the soul is an integral part of a person, then it is the part of the person that exists in the spiritual part of our reality and is not separate at all.  If this is the case, why does it survive after our physical death?  Perhaps it is similar to exfoliating dying skin cells or hair.  Perhaps the soul has many such bodies and sloughs them at various parts of its life.  Perhaps with the dying of one body, the non-physical body then grows and develops a new one.  This would, of course, explain reincarnation.
However, if the soul is not integral, but in fact a spiritual symbiote, then I am curious as to how it came to be there.  What spiritual thing decided to piggyback on an animal and raise their consciousness to that higher state?  My guess is dying gods.  What happens to the old gods?  Where do gods come from?  Any spiritual being that is nourished by belief is a god, no matter how insignificant.  The more believers, the greater the god.  A once great god who no longer has believers must therefore perish without sustenance.  Is it possible that these old gods, these forgotten deities found some way to live by obtaining host animals for support?  Homo Sapiens.  This may not be as far-fetched as it sounds.  Think about it.  What makes everyone feel good?  When people believe in you.    When you know that you have support from friends or family, that people believe in you, that you are being acknowledged in that belief, that is when you do you best; feel your best.  Perhaps this is why it is so important to believe in oneself.  The old gods were born in our human bodies and essentially need the belief of one person, its host.  Perhaps this is why so many people spend their lives looking for others to believe in them.  The gods that ride them have old habits to break.  Perhaps, also, this is why the body dies and the god lives on; to keep trying to learn to be free of the belief of others.