Maybe
UFOs, as in I have seen a couple of aerial objects that I could not identify.
Cryptids- never seen one but twice heard an unexplained vocalization in the woods. I and the others who heard it could not explain it, but am not willing to say there's no other explanation than bigfoot.
Ghosts- pretty strange goings-on in houses I have lived in and a shop where I once worked. All but a few could be explained away
.
God- sometimes
Not At All
Conspiracy theories - Sometimes a terrorist attack/assassination/naturaldisaster/moonlanding is just a terrorist attack/assassination/natural disaster/moon landing, and no damn body from the US government is going to show up and confiscate anyone's firearms
The Devil- there is evil in all of us. There is no need for a specialized entity in which to house it all.
The "End-Times"- been predicted for millenia, not gonna happen till the sun burns itself out or the earth is hit by a giant asteroid. My especial pet peeve.
Things I do believe in-The ability of most people to overcome evil and be kind
The health benefits of marijuana
Myself and my abilities