I would like to point out your first paragraph and your last:
Stephen Hawking, a theoretical physicist, said: "Because there is a law such as gravity, the universe can and will create itself from nothing."
So to those that adhere to the teachings of scientists such as Hawking. How is it that No-thing = Some-thing?
You do know what the word “theoretical” mean in association with “physics” or with “physicist”, don’t you?
It mean, a large parts of his works involved in using maths to provide a feasible solution to a draft (or proposed) explanation.
So unless, the physicist in question discover some evidence or provide test results from some experiments that support his concepts, his explanatory models aren’t “scientific theory”.
Much of Hawking’s works are theoretical, not tested, not supported by evidence, therefore they aren’t accepted as science.
Science - and I mean real science - science required some testable and measurable evidence, needs to be falsifiable, and needs to be reviewed by peers.
Much of works are mathematical feasible, showing that he is very much capable of thinking outside of the box, but in the real world, they are largely untestable and untested.
While I admired his inquiring mind, I don’t adhere to any of his works, if they are untested or lack verifiable evidence.
Hawking have been corrected by less well-known physicists.
Don’t get me wrong, Eyes to See. Some theoretical works have been known to be correct, testable and tested.
For instance, Peter Higgs formulated a very theoretical papers on the Higgs Mechanism that explain how mass is generated, way back in 1962. It was only in 2012, they were be able to test for the Higgs boson, using the Large Hadron Collider (LHC) at CERN.
It took 50 years, to get the first evidence. So Higgs mechanism is no longer purely “theoretical”.
Likewise, in 1948, Gamow, Alpher and Herman predicted the Big Bang Nucleosynthesis (BBN) and Cosmic Microwave Background Radiation, and they were theoretical until it’s discovery in 1964, by Penzias and Wilson, thereby providing evidence for the Big Bang theory, at the same debunking Steady State model that was proposed by Bondi, Gold and Hoyle in 1948.
So it may take time to verify any theoretical concept with evidence, especially when they could develop technology capable of testing such concepts. It did with both the Big Bang theory and with Higgs mechanism.
Some theoretical models have become scientific theories, while others have failed. So there is possibilities that one day, some scientists may be able to test Hawking’s highly theoretical models, and may one day be valid and verified. Or one day, Hawking is simply wrong with his concepts.
Anyway, I am not willing to accept any of Hawking’s (theoretical) proposals until they have been rigorously tested.