“If”….that takes us nowhere. Fortunately, the laws of physics aren’t “iffy”. They maintain a constant.Not really. Conservation of energy is a consequence of Noether's theorem and is true so long as the laws of physics do not change with time - which is what we empirically observe today and in the past in the observable universe. But if it was not always so, back in time beyond the reach of our observations, then all bets are off.
That "God" is the "source" of all energy is a mere assertion, unsupported by evidence: a purely religious statement.
And in fact, it’s those very constants, their uniformity and reliability, that does provide a reasonable basis for saying there is one Creator of the design and finely-tuned parameters we observe. Denying this integrated complexity, and the around 50 ideal tight constraints imposed on them, is imo just reflecting a bias, a hope, which is “unsupported by the evidence”.
Have a great day.