I am not formally educated in physics but I understand the idea of 1+-1=0 and the hole digging example.
At a basic level we need to take something to create something else; removing raw materials (-1) from the earth (0) to make a brick (1). Should we decide to dismantle the brick and put it back in the earth (assuming we would be able to retrieve all of the material lost through natural loss, evaporation and transfer of microscopic particles) we would have what we began with: 0. This isn't to say absolute zero, but simply "what we began with" (I think it might be more useful to substitute ‘0’ for another mathematical symbol but that’s not something I would know).
I start with a small example for ease of explanation, when we look at it on a larger scale we will see that there are variables but the concept is the same.
If we broke all of our man made materials; buildings, bridges, computers, kettles and organic material such as plants and animals down into their most basic form, we can see that everything on earth came from the earth - we would return back to 0. But would we? Stuff is always being added to the equation, meteors hitting earth & other space debris. Just the same as stuff leaving the equation as in normal losses and even in the forms of our man made satellites being created from earth materials and then destined to drift through space or crash land on Jupiter. If, however, we could control these variables – bring all lost materials back and expel all foreign materials, then yes we would return back to 0.
I've digressed slightly but my point here is that if the original equation remains true, we can expand this to a more universal solution:
If in the original example, a hole is -1, flat undisturbed land is 0 and a pile of soil is 1 then, all of the matter and energy in the universe is 1, the theory of dark matter and negative energy is -1 and x is 0 (can't quite grasp what x is just yet).
Alternatively the big bang theory provides another way of reaching -1; all of the matter in the universe was created by the big bang. This would mean that there would have to have been something before the big bang for all of our universal stuff to have come from. This is, of course, assuming that our equation still holds ground at such a universal level.
I don't understand much about quantum mechanics but from what I have read, it is thought that there could up to 11 dimensions. Without getting too far into a different topic, I think I read somewhere that quarks often pop in and out of existence from different dimensions. Please forgive me if this is entirely incorrect, but if there is any truth in this, it would provide us with a way of accounting for the -1 in our equation.
As for the god argument, you could either debunk his existence by using either one of the previous theories, or prove his existence by saying that he is the -1 that all of our stuff derives from.
Having said all this, I’m curious to think what everyone’s thoughts are on what x might be if universal stuff is 1 and any of the above are.-1.