Mr M says " knowledge has banished fear!" What does he mean by this?

Mr. M speaks this quote during a conversation with Isabel about her expectations and first impressions at the school in the location. Isabel tells him that she was initially confused and scared about the idea of spending time with black people as equals, but quickly came to see it as normal and enjoyable, especially once she got to know Thami and Mr. M. Mr. M puts this concisely as "knowledge has banished fear" (p.29), which could also be seen as a general moral of the novel, especially in the eyes of Mr. M, who values education, books, and knowledge above almost all else.