Sadly, I have the same composition teacher as Austenite, but! As I've gotten older, I've decided that pushing back against a teacher with whom you disagree can be one of the most formative learning experiences you will ever have. If you can stop worrying about the grade, and seek to express your ideas in opposition to theirs, that will help you crystalize your views and learn to really think for yourself. Having someone take the opposite view forces you to really examine your ideas and getting a little mad can lead to some really sterling work, as you seek to prove irrefutably that your ideas are worthy. You will learn what is good, and also, what does not stand up to argument. You will get a little closer to truth and beauty as a result.
Although, sadly, particularly among younger students, there will be many who won't know that they are allowed to push back against a professor, or who worry that a bad grade will keep them from being allowed to take the next step academically. It's an important life skill to learn to argue politely and respectfully, but still passionately. Probably comes easier to those of us with siblings. (: