Diversity strengthens a community because everyone in it can learn something. For an example, each culture is taught and brought up a different way. The things they've learned may be different from the things that you were taught. Diversity can teach you to appreciate other cultures and how deal with new experiences when you go to different places. When a community can be accepting and understanding it actually makes the community better.
Your first paragrap you introduce your argument, the background info. Include a thesis at the end. The second paragraph: The first point of your argument with proof. (2nd paragraph) The second part of your essay (Third paragraph) is the second point with proof, the third part is the third fourth point. The last is the conclusion with a summary and memorable ending