The most important moral lessons from the book are: being a good person is more important than wealth; good deeds will come back to benefit you; bad deeds will come back to haunt you; family is the most important wealth; and true love is classless.
The first lesson is that being a good person is more important than having wealth. Pip is concerned more about being a gentleman than being a good person. Pip tells Biddy that he has “particular reasons for wanting to be a gentleman” (ch 7, p. 89). He wants to marry Estella. Yet as a gentleman, all he seems to do is run up bills and run around in London with his new friends. Biddy is the calm, patient one. She is the good person.
Good deeds come back to benefit you. Some people call this karma. It’s like a boomerang. When Pip helps Magwitch, he benefits from it because Magwitch gives him all his money to make him a gentleman. If Pip had not helped the poor convict by bringing food and a file, he would never have had his expectations.
“They shall be yourn, dear boy, if money can buy 'em. Not that a gentleman like you, so well set up as you, can't win 'em off of his own game; but money shall back you!” (ch 39, p. 217)
Every bit of money Magwitch earned went to Pip, because Magwitch was so grateful for what Pip did for him.
Just as good deeds benefit you, bad deeds also come back to you. Magwitch eventually got back at Compeyson, in a way. Estella got back at Miss Havisham. Miss Havisham treated her badly, turning her into a cold, emotionless wreck. Then she wondered why Estella did not have any affection for her.
"[Look] at her, so hard and thankless, on the hearth where she was reared! …where I have lavished years of tenderness upon her!” (ch 38, p. 206)
Estella tells Miss Havisham that she is what Miss Havisham made her. She is cold because Miss Havisham made her cold.
Pip comes to realize that family is the most important thing in life, but he realizes it too late. He turns his back on his home, mostly Joe, because he feels that he is better than Joe. He only realizes later what he was missing.
Joe became a little less easy with me. In my weakness and entire dependence on him, the dear fellow had fallen into the old tone, and called me by the old names … that now were music in my ears. (ch 57, p. 315)
Now that they are both adults, and Pip has gained and lost his fortune, he realizes that he had the best wealth of all in a kind family like Joe and Biddy.
Finally, when one is really in love, class does not matter. Pip is concerned with making himself a gentleman so he can marry Estella. It was the wrong goal and for the wrong reason. Estella could never love him, regardless of his class. She cared about him, at the end, even though he was poor—but she still could not love him.