Given the magnitude of and craftsmanship in The Great Gatsby, there will be no shortage of quotes for you to use here. One of the best quotes that captures so many of the themes identified would be in how Fitzgerald describes life in the 1920s:
They were careless people, Tom and Daisy--they smashed up things and creatures and then retreated back to their money or their vast carelessness, or whatever it was that kept them together, and let other people clean up the mess they had made...
Within this one quote exist the themes identified. The disillusion and hope is seen in how people acted in the 1920s. The hopeful element of celebration and joy is undercut with the destruction intrinsic to it. The lack of responsibility is one of the most striking features of the quote, and reflective of its overall lack of hope and lack of morality. There is no regard for the consequences of individual action. The decay of the American Dream is evident in this quote, as well. There is a hollowed out vision of the American Dream in which people see what they want only to "smash" it up. Time passes in how people like Tom and Daisy "let other people clean up the mess they had made." In this quote, Fitzgerald captures how crushing dreams can be, and how individuals themselves fall apart under the weight of such dreams. This becomes the ultimate reality that leaves the individual feeling empty and hollow upon seeing their vision realized.
Quotes with multiple thematic applications litter The Great Gatsby. The key element to keep in mind is how Fitzgerald develops these quotes to encompass multiple themes. For example, the above quote about Tom and Daisy can fit more than one theme. This is seen in other quotes in the narrative and the ability to think in a divergent manner about how such quotes can fit thematic contexts is one of the reasons that this work is so powerful and why Fitzgerald has to be considered a writer of considerable talent.