What is the most important aspect of an Essay?

I believe the most important aspect of an essay is the thesis statement. Even though it is just one sentence out of many in an essay, it holds the most importance as the basis of an essay. The thesis needs to direct all ideas and points that will be discussed in the essay very thoroughly without giving away to much information. It should be very specific; however, not give away any concrete examples that will be mentioned later on. For instance, in the student sample essay A for Alfi, the author establishes that he will be making connections with the characters in Pride and Prejudice to “good lists” and “bad lists”. Therefore, we know what he will be talking about and we won’t be confused about the context of the essay.