"Believing" in ghosts means believing in existence after death. It means that one believes that consciousness exists past mortality.
So,if you believe in ghosts, then nobody is temporary. Not you, not your family and friends, loved ones or heroes. So death becomes a promise of immortality, rather than marker of simply ceasing to exist outside of the memory of others.
Also, it implies a higher power or God. Or a supernatural hierarchy. Which mens that that the idea of justice transcends mortality. So, Hitler's tortured, your mom's an angel and you'll reunite with her after your bout with cancer, or a car crash or a piano falling on your head.
Personally, I don't believe we exist after death, BUT, quantum physics, of all things, suggests that we all my be eternal. Scientific hocus pocus aside, I think our biggest downfall as a species is that we factor in the idea o an afterlife into self-existentialism. If God stopped existing in our browns, morality and emotion would not. Which means that we could only blame nature and ourselves for our shortcomings. Which ultimately means that we could only blame ourselves.
Ghosts and whiskey are the same damn thing. The difference is that whiskey lets you stop fearing ghosts. Ghosts lead you to fear whiskey.