I think this needs to be said again;
Being afraid of uncertainty i think is the major factor in all metaphysical thinking.
When you begin to understand the implications of not being able to know weather or not you have a soul or if there is or isn't a god, you will begin to understand the psychological insanity and delusion those must undertake to tell themselves they are certain of something that holds no claim to certainty... and probably never will.
"I know!" you tell yourself. "I know I know! I Just know!" you repeat over and over. The truth of this matter is, that you do not know... and this fills you with fear. When making up an answer in order to deal with the fear of not knowing, one must become insane and delusioned, this is the only way one can hide from the fact that he/she is not certain.
Don't be afraid, nobody knows, you are not alone.