@Frank Apisa,
You seem to be seeking a universal definitionof "having belief in" that can be applied to God, Batman and Flying Saucers. I am not sure you will find one, however I do not believe my original definition is flawed. It well describes the term that Christians use when describing their belief in God and/or Jesus, and is not at odds with the dictionary.
I would use a different definition for Batman, and again for flying Saucers, but rest assured my friend, I would never apply a definition of belief to you