What a broad question! I guess your answer to this is obviously going to depend on what you personally "took" from the novel, but for me my two lessons are based around the nature of a true "gentleman" and secondly the danger of trying to manipulate and interfere with somebody else's life.
One of the central themes of the novel is based on the difference between gentlemen and gentle men. The difference is key. We have characters such as Compeyson who are clearly gentlemen and yet are shown to be lacking in any true moral fibre - just because they know how to dress and act in high society does not make one a gentleman, Dickens seems to be arguing. On the other hand, we have a character such as Joe, who laughably does definitely not fit into the character of "gentlemen" - just take his first visit to Pip in London - and yet is imbued with such dignity and gentleness as to clearly denote him of being of higher moral calibre than characters such as Compeyson, and even of Pip himself. Money and social understanding are not the only exclusive ingredients to produce gentlemen - the message is clear.
Secondly, the novel shows the danger of interfering in somebody elses life and trying to force another person into the shape of your choosing. Whilst this is exhibited in the relationship between Magwitch and his desire to "make" Pip into a Gentlemen, it is most clearly exemplified in Miss Havisham's creation of Estella as a heart breaker so she can vicariously have her revenge on Compeyson and, indeed, on all males, because of her being jilted. Miss Havisham succeeds so well that Estella is unable to love anyone - not even her maker. Miss Havisham's grief at this discovery and her final realisation of the magnitude of her crime in this regard clearly indicates the dangers of trying to make others into things we want them to be.
Another very important lesson that the reader can learn from having read Great Expectations by Charles Dickens is the lesson that Mr. Jaggers dictates to Pip on more than one occasion:
Take nothing on its looks; take everything on evidence. There's no better rule.
Pip has been deceived by the stellar appearance of Estella and has fallen in love with what he has perceived to be a young woman of breeding and class. He further deludes himself into believing that Estella will love him. Likewise, he is impressed with Miss Havisham because of her wealth, and he deceptively believes that it is she who is his benefactor. And, because Estella has called him "common," Pip believes himself inferior to her just as he considers Joe to be inferior and common. Because Pip has judged by appearances, he accuses himself in Book the Second of being a self-swindler as he avoids Joe by staying at the Blue Boar upon his return to the marsh:
All other swindlers upon earth are nothing to the self-swindlers, and with such pretenses did I cheat myself.
Still another lesson the reader can attain from Dickens's classic is the meaning of real love and friendship. This lesson is best demonstrated in the character of Joe. From the beginning of the novel, Joe displays a golden heart, open for a poor, neglected orphan. He shelters Pip from the wrath of his sister, he instructs Pip in moral values, he praises the boy when he learns his school lessons, he never derogates Pip. Always he loves him generously, even when Pip is embarrassed to be in his company. For, then, Joe tells Pip that he will not visit him in London since he "belongs on the forge." When Pip avoids seeing Joe, the man yet loves him, coming to treat his burns from the fire that have consumed Miss Havisham's decaying dress. Joe comforts Pip with the tender words that he has always used, "Ever the best of friends, Pip, old chap. Ever the best of friends."
What better example of loving friendship is there than in the character of Joe Gargery?
1. Another lesson that one can take away from Great Expectations is that social class certainly does not exemplify a person's intelligence, character, or generosity. Almost all of the upper class or "learned" characters in the novel are classless. They use one another and others from the lower classes and dispose of humans when they have obtained what they want from them. Miss Havisham, Drummle, Estella, Jaggers, and even Pip for a while demonstrate this truth. Dickens makes it clear that generosity and character stem from a person's soul rather than his social status--Biddy, Joe, Magwitch, Mr. Wemmick, and Herbert illustrate this truth. They are goodhearted humans who are generous with their intelligence, social savvy, or money (if they have any).
2. Second lesson--Dickens (and many other male writers) seems to portray most male characters as being easily manipulated by women. While Miss Havisham is tricked and jilted by Compeyson and her brother, she teaches Estella to manipulate as many men as possible, and when Estella arrives upon the London scene, she does just that--skillfully. Similarly, while Joe tells Pip that he married Mrs. Joe so that he could care for her and Pip, she obviously manipulates and dominates Joe and almost any other male with whom she comes in contact! This could be Dickens' way of including some of his own experiences in a fictional work. He was in an unhappy marriage himself and became extremely disillusioned with marriage and family later in life.
I suppose the first lesson is that money or status can really change a person and that we should not let it do that. In the book, Pip gets money and status and that really makes him a very different person.
The second lesson I would take from the book is that we should be more grateful to those who help us. Pip gets help from Magwitch and from Joe but he disdains both of them for a long time. It is only at the end of the book that he comes around. To me, the fact that he treated the two of them the way he did is pretty disgraceful.
The moral theme of “Great Expectations” is very basic. It is an old moral theme that has been around as long as man has walked on this earth. Pip, and the reader, learns that affection, loyalty, and conscience are more important than social advancement, wealth, and class. Charles Dickens creates this theme and the novel is based on Pip learning this very lesson. Pip spends the novel exploring ideas of ambition and self-improvement. Pip is an idealist and if he can think it up, and if it is better than what he has, he wants it. When he first sees Satis House, he decides he wants to be a wealthy gentleman; when he thinks of his immorality, he tries to be better; when he realizes that he cannot read, he longs to learn how. Pip's desire for self-improvement creates “great expectations” about his future.
Pip has many expectations, but I think the main expectation in Dickens' novel, and the one to which the title refers, is that Miss Havisham is going to do something wonderful for him. When he learns about his great expectations from Mr. Jagger, Pip naturally assumes that it is Miss Havisham who is his benefactor. He guesses that she wants to turn him into a gentleman, then have him marry Estella, and finally leave him all her money, so that he can enjoy a life of ease and luxury with a beautiful wife. In the process of becoming a "gentleman" he experiences some disillusionments, but there are incidental to the main expectation that he is going to be married to Estella and inherit a fortune. Neither Miss Havisham nor her lawyer Mr. Jagger say anything to discourage him. Jaggers has to keep silent for professional reasons. Miss Havisham's motives are harder to understand. She knows what Pip expects of her and doesn't tell him the truth. But he is in for a terrible shock when Magwitch, his real benefactor, shows up on a cold, rainy night. Dickens must have planned that scene from the time he began writing the novel. Pip's whole life and perspective are changed by the fact that his social status was dependent on one person rather than another.
One lesson is that money does not buy happiness. Pip assumes that he is miserable because he is poor, and Estella will care for him once he is rich. Neither is true. Money does not make Pip happy, it only confuses him. Everyone wants him to become a gentleman, but he learns that gentlemen are not necessarily happy, and it is not necessarily right for him.
Another lesson is that love is painful. Most of the cases of romantic love are passionate and one-sided. All of the passionate loves in this book turn out badly. It is almost as if Dickens is saying to us that love is a myth. Find someone you are comfortable with, and you'll be happy. Chase someone you're passionate for, and you'll be miserable.
There are many moral lessons in this novel. The main one is that wealth cannot bring happiness. and that appearances can misrepresent reality. When Pip visit the Satis House, everything contradicts what Pip's definition of rich. It is a worn-old house and sunshine never comes in the house. Estella has been raised to led an unhappy life, cruel and incapable of love. In later chapters, Pip will meet a convict, Magwitch. During that time, convicts are regard as being bad. However, Magwith turns out to be a compassionate man who works hard to give "expectations" to Pip in return for his kindness Pip shown when Pip give food to him many years ago.
Meant our lives today?