Chapter XXXIX records the most momentous event in Pip's entire life. This is where he learns that Magwitch, and not Miss Havisham, has been responsible for all his great expectations.
All the truth of my position came flashing on me; and its disappointments, dangers, disgraces, consequences of all kinds, rushed in in such a mutitude that I was borne down by them and had to struggle for every breath I drew.
Poor Magwitch is proud of himself for turning an ignorant country boy into a London gentleman and does not realize how horrified Pip feels, perhaps especially at the realization that Miss Havisham had not become his patron with the intention of grooming him to marry Estella.
"Yes, Pip, dear boy. I've made a gentleman on you! It's me wot has done it!....I lived rough, that you should live smooth; I worked hard that you should be above work."
Magwitch's idea of a gentleman is a soft, lazy man who has lots of money to spend and doesn't have to work for it. Pip has become what Magwitch has made of him.
Pip doesn't want to take any more of Magwitch's money because he sees how the underprivileged of this world look up to gentlemen and ladies who, like Pip himself, are only selfish, useless parasites. Magwitch's joy in creating his very own gentleman only makes Pip realize what he has become--a fop infatuated with a "lady" who is no better than he is and idolizing a selfish old woman who let him believe she was his benefactress when she was only tossing him a few coins. The rich do not get rich by giving money away.
What saves Pip is his working-class background. He is not a "real" gentleman--not completely spoiled by idleness and privilege--but a sort of half-gentleman who still retains the virtues and values he acquired from Joe Gargary and to some extent from Biddy.
Gentlemen and ladies act the way they do for self-protection, to erect barriers between themselves and the lower classes. We can see in Great Expectations the pervasive influence of the French Revolution, with its ideals of liberty, equality, and fraternity--an epoch-making event Dickens wrote about in his novel A Tale of Two Cities, which begins with the wonderful words:
It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair....
Dickens was not a revolutionary or a nihilist but a religious man whose writings undoubtedly did more to change social conditions on both sides of the Atlantic than the preachings of any number of revolutionaries.