What does the relationship between Herbert and Pip reveal about the true nature of friendship? How does this relate to one of the major themes in the novel?

Herbert is what most would consider a true friend to Pip, since he does not desert Pip when things go badly for him. Herbert is will to do what must be done to help Herbert achieve success in his quest for his "Great Expectations." And one idea, those that are truly supportive of us will always be around, helps the reader understand just what a good friend Herbert is.