BTW, the dispute here concerns "matter", not whether or not God exists Wouldn't this refute that?
Hawking, however, says “the universe can and will create itself from nothing” because there is a law such as gravity.
He's not indicating that God will create something from nothing, only the universe.
Look, you people are getting caught up with semantic differentials. Energy is "something"; matter is "something"; laws (and fields) are "something". You can convert energy to matter, and matter to energy. With particles popping up out of the vacuum all the time, gravity is not just on its own.
The Universe may well "self-assemble" because of the existence of the laws.