Totally he was risking his life to save Harry Potter. Well really he loved Lilly Potter but she died so he saved Harry. He was a spy for Dumbledore he pretended to be a death eater but he was really a good guy!
without reading the books and only watching the movies he looks bad but once you read or see his memories you'll realize that he isn't as bad as he was made out to look so I'd say no he's helped Harry through the years more then hurt him