the creation of the heavens and the earth was one. Along with breathing into Adam the breath of life and making him a living soul. That's pretty magical, when you think about it. It seems pretty competent to me. How many of us can do that?
So, if He did that, turning water into wine is not that big a deal. Jesus did miracles to prove to the Jews who he was, since they knew ahead of time that Messiah would reveal Himself by doing miracles.