I do believe that wishes come true but this may be a bit misleading. I don't think they come true simply because you make the wish. I think they come true because people believe in and work hard for the things they wish for. Hard work is what makes wishes come true.
If you believe in a wish hard enough it will most likely come true. This is not due to some magic taking place. It is based on the simple fact that believing in something so much will cause you to work toward getting what you are wishing for. Eventually, if you keep believing, the wish will come true.