you see ma fren , not everything can be backed up with solid evidence , if you know you know
I agree that not everything can be backed with solid (physical) evidence, however you do require a rational reason to believe something. So what is your rational reason for the belief in evil spirits?
"Religious people believe God exist, but there is no solid evidence to back that up."
This i agree with. I do not understand why someone would choose to believe something without evidence.
"Atheist on the other hand do not have solid evidence on the origins of the universe, they talk about the "big bang" but then again its just a theory."
The origins of the universe isn't what this particular discussion is about. However, we shall address this statement since it involves evidence which is the issue at the heart of the matter. All the
evidence we have, cosmological background radiation, calculations etc very strongly suggest there was a time there was a point where everything was a singularity. The big bang explains the expansion from that singularity.
However, this is not pure conjecture. It is based on
mountains of evidence and models (like any other
theory you can think of e.g theory of gravity, relativity, thermodynamics etc) which all point to this being the most likely case among all other proposals for how the universe began.
"Sometimes you have to experience stuff to believe."
While experiences do shape beliefs, you have to agree that your experience could be wrong, for example; having auditory and visual hallucinations. Or you have been deceived by people to make you believe something that it isn't.
Even if you did genuinely experience something that neither you nor anyone else can explain, what you then have is an experience with no explanation. If you decide to label it a "evil spirit", then you have now given it an explanation and we are back to the beginning. You have the burden to provide evidence or a rational reason to give it this explanation/label.
So again I will ask, how do you back up your claim that evil spirits are real?