I don't know that I could be convinced. If a very powerful being showed itself to me and performed what appeared to be miracles, I would assume an alien like Q from Star Trek. I don't know how it could demonstrate that it is actually the creator of all things. I don't suppose it really matters because whether it is God or a being like Q, I'm probably going to treat it the same way.
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.
Albert Einstein
Albert Einstein