'He has been a faithful member of First Purchase since he was a boy.'

Here, the people of Calpurnia's church are talking about Tom Robinson. It reflects on how Tom is a good person. He is unlikely to be the type of person to rape a girl. The people of his church community are all sticking up for him and helping his family while he is unable to support them showing that they dont belive what he has been accused of. It also shows how Tom Robinson is a kind and faithful person and completly the opposite to how the Ewells describe him.