I think that one of the best scenes with quotes that represent the idea of belonging would have to be the courtroom scene where Mary Warren is being mocked by the other girls. Mary's weakness for and her desire to belong are both evident in the scene. She capitulates on the stand because she cannot envision being separated from the group, and to belong to them is more important than anything else. This same dynamic of belonging to the group at all costs is evident in the second scene in the first act when Abigail is wrangling the wills of the other girls to "stick to the plan." She is forceful in the idea that their notion of identity has to be linked to one another. When others voice weakness in embracing this aspect of identity, she is strong and dominant in ensuring that the identity of the group trumps all other individual elements. I would also say that Proctor's closing speech is representative of the idea of belonging, as he seeks to belong to something more transcendent and elevated than either what he had represented or what Salem represents at the time. The closing speech that Proctor gives talks about the idea of Proctor seeking to belong to something that is more encompassing than the contingent setting of Salem and the contingent manner within which Proctor had been seeing himself.