When your writing is inconsistent, it gives the impression that you don't have things "together." When you write consistently, you look to know what you're doing—even if you don't. The format should be uniform regardless of length. All of the indents should be the same. Tabs should be set to the same size. Everything should be the same color. Inconsistent spelling and grammar also give the impression that you don't care about your work. If someone were to read your document carefully, they would not only find errors but also misunderstandings due to unclear word choice. They would not get the message you want them to get. Finally, inconsistent formatting is a pain to read. If you've got long paragraphs or sections without any kind of indentation, it's hard to tell where one sentence ends and another begins. You'd need to scroll up or down to see everything that was written. This is especially problematic for those who print out their documents since they then have to manually fix all of the inconsistencies. In conclusion, writing is a form of communication, and poor communication can lead to misunderstanding and error. Therefore, it is important that you are consistent in how you write so that everyone understands your message accurately and enjoys reading through your content.