All books have themes and lessons in them that teach us something important after reading them. Sometimes these lessons are learned from the characters of the books. In The Great Gatsby, Jay Gatsby teaches us lessons about success, hope, and ethics or morals. Many of the characters in The Great Gatsby are used to construct different themes and teach us moral lessons.
Gatsby has been in love with daisy for many years. Gatsby uses illegal and unethical ways to acquire wealth that he thinks he needs to have Daisy's heart. Since Tom and Daisy have a large house, a luxurious life, a comforted lifestyle, Gatsby feels he must have this too to win Daisy's heart. In fact, Gatsby tried almost every single thing that money could buy to try to satisfy his love for Daisy. He often threw extravagant parties with hope that she might show up and see him in all his wealth.
"I think he half expected her to wander into one of his parties, some night, but she never did." Gatsby never confronted her and told her his true feelings. And in the end the two never got together. Gatsby in reality was a lonely and unhappy person with no true friends. In fact only 3 people showed up to his funeral. This lesson shows that money cannot buy happiness.
They characters in the novel are corrupt in the way that they do not care for anybody but themselves. They are selfish and controlled by wealth and money. Love and happiness are things that can never be bought. For instance Tom and Daisy are married and have a child together, but they both still commit adultery. "They were careless people, Tom and Daisy -- they smashed up things and creatures and then retreated back into their money...