I believe that cheating is a terrible thing to do and will hurt you in the long run. When you cheat on a homework assignment, quiz, or test, you are only cheating yourself. You should be honorable enough to take a bad grade and admit that you don't know everything.
When you cheat in school, you are just getting by, you aren't actually learning. Later in life, this can really hurt you. When you grow up and have a job, there will be no one to copy. None of the good employers will want you if you can't do good work -- and that means undesirable, dead-end, jobs like flipping burgers.
Cheating is also dishonest and dishonorable to yourself and other people. It will cause you to lose your self respect and the respect of others. Cheaters never really win, they only fool themselves.
For these reasons, I believe that cheating is a terrible thing to do. It may get you a grade, but that grade sure won't help you in life. Learning to respect yourself is what will.