I agree with Ragman answer, People need their believes because they are
grown up with them and it has a historical explanation. If you empty them
from their believes they can not find any substitute for them. Believing in God
and ... most of the time helps people and of course can explain a lot of strange
things in human life. God is the MOST SIMPLE ANSWER people can say for
their questions. Most of the people do not have logical explanation for their
believes , They just follow their society and family culture.
My idea about strange things that people usually relate to ghost or God ...
is that history shows us it can be a scientific explanation for them that discover
in future. For example some time in the past people thought rain have a God
who control it but now science have an answer for how it rains and when it rains.
Actually the idea of existence of God was for the phenomena that people
could not explain them. And now we inherit them but I can not accept them.