The Question and Answer section for The Great Gatsby is a great resource to ask questions, find answers, and discuss the novel.
This happens in Chapter 8. Gatsby and Nick have a long talk about Gatsby's past. Gatsby confides that initially he just wanted a bit of action with Daisy but fell in love. From then on he never felt worthy of her because of her high social status....
For Nick, the green light is a symbol of motivation.... the things we reach out for..... work toward.
Are you looking for a specific passage in chapter 7?