What does Great Expectations tell us about kindness?

Great Expectations repeatedly tells us that kindness is one of the most important traits a human being can exhibit. Characters in the novel are at their best when they are being kind to another person.
The young Pip, for example, shows kindness to the convict Magwitch. Although he brings him supplies because the man threatens to tear out and eat his heart and liver if he doesn't, Pip also notes that Magwitch looks cold and hungry, and thinks as he works that night stirring a pudding of what it must be like to have an iron chain attached to one's leg. He goes above and beyond when bringing food, including bringing brandy and a pork pie, which he didn't need to bring. As we know, he is well rewarded for this kindness, which Magwitch never forgets.
Joe is another example of kindness in this novel. He is a welcome refuge for Pip from his harsh sister, and even when Pip becomes a gentleman and feels too good for him, Joe never wavers in his friendship and kindness towards Pip, paying his debts when he has nobody else to turn to. Joe is surrounded by Biddy and Pip's love.
People who are brought up to be unkind, like Estella, suffer unhappy adulthoods, and people who have been subjected to unkindness, like Miss Havisham, and pay it back to others, suffer. It hurts Miss Havisham very much that the adult Estella cannot love her, but as Estella points out to her, it is the product of Miss Havisham's teaching that she became cold and heartless.