Ghosts exist or we are all from same root

Tweet

Hey I've this question in my mind that how come holy books written many centuries ago carry same ideology about ghosts when there was no internet, phone, aeroplanes or other way of communication when relgions had been developed far away from each other. Many people don't believes in ghost but they are so much considerate about their religion so I must say either ghosts or bhoot or zin or any other evil power truly exists or we are all from same religion which with time get branched into new ones and we are just fools to fight for nothing or should I say we are damn war seekers. What do you think ghosts real or we are one with no religion ?