If you write something, then you should edit it, because writing editing is an essential aspect of writing activity at all levels. Maybe you think that if you are student, writing editing is not obligatory, because your writing works are not so important than for example some masterpiece by definite writer.
As for professional writers, they really need writing editing. Sometimes potential best-seller may be a failure if whole content is presented in language, which is difficult for perceiving and understanding. It is possible that writer has excellent idea for a novel, he can tell every detail, but written variant of genial idea may be terrible because of grammar and spelling mistakes and because of linguistic and stylistic defects. If author can’t control this moment by himself or herself, he or she hires editor or corrector who corrects mistakes.
Author may afford to hire corrector, because he or she earns enough money for it. But students usually don’t have such financial source as high salary, because teaches unfortunately don’t pay them for their essays or courseworks, which according to students’ opinions, are real masterpieces. That’s why, if you are a student and your academic papers are far from to be considered as masterpieces and you can’t find corrector or editor for free, you should do such work as writing editing by yourself. At least you may ask your friend or teacher to look at your paper and they may notice some defects, which you have not noticed. If not, take grammar book and orthographical dictionary and begin writing editing.