Spoilers for Werewolf by Night #32 (1975), Marvel Spotlight #28 (1976), and various other comics featuring Moon Knight.
Moon Knight is a superhero character with Dissociative Identity Disorder (which is still more commonly known as Multiple Personality Disorder). His main identities are Marc Spector (a former mercenary), Steven Grant (a wealthy socialite), and Jake Lockley (a cab driver). While he has a few other personalities his constant identity is Moon Knight. He first appeared in Werewolf by Night #32 as a foe to the character Jack Russell (the titular werewolf). In this appearance he is a villain. However, his following appearances end up retconning him as the mentally unwell antihero he currently is (Marvel Spotlight #28 and Moon Knight #2 ).
Yet, there is more to Moon Knight than just multiple identities and a basis in the supernatural side of a superhero universe. In fact his belief in the ancient Egyptian deity Khonshu allows writers to play with what belief means. For example in some stories Khonshu is an actual deity that Moon Knight, and some other characters, actually interact with (Moon Knight Annual #1  and West Coast Avengers #22 ). While in other stories Khonshu’s existence as a literal deity is questionable (Moon Knight: The Bottom ). There is even one story where Khonshu is just another alternate personality Marc Spector has from his mental illness (Moon Knight #200 ).
Though Khonshu’s legitimacy is seemingly constantly in flux, the various stories do provide great examples of how belief can work. In other words, one can look at the stories in the same way one looks at politics, religions, or whatever. For instance one can look at differing beliefs as weird and not worthy of merit, much like what happens in Moon Knight: The Bottom. Or one can see some truth in others beliefs and try to accept other people for who they are. This somewhat occurs in the events of Moon Knight Annual #1 and West Coast Avengers #22 with Marc Spector and Clint Barton/Hawkeye respectively. However, there are other times where a belief can be due to illness and one must disregard it as a falsehood; as is the case with Moon Knight #200. In conclusion while we should try to accept beliefs we should not have any belief define everything we do or think.