"they believed Jesus from Nazareth was the Messias and the other jews did not believe jesus was the messiahs"
Isn't that definition in opposition?
Isn't that definition in opposition?
group A believes in X
group B believes in Y
What the parent poster seemed to imply was
group A believes in not Y.
Or a more concrete example of today, many people today define themself by being anti green, anti progressive, anti woke, antifashist etc. but often struggle to define what they are standing for.
And because beliefs tend to be on a bit of a continuum, what starts with A believes Z <= 4 and B believes Z >=5 evolves to A believes Z <=1 and B believes Z >=9, and both believe anyone who believes 3<=Z<=7 is not part of their group.