one I've recently heard is essentially 'no natural laws can exist without God',
Well, the way I see it, it's a proposition or assertion. That is it's only the beginning of an argument or truth claim. It's not a complete argument.
So the standard follow-up questions are:
1) What makes you say that? What's your reason?
2) Why do you believe it?
The theist's answers to the two questions given above are usually the ones in which those questions are either ignored or met with silence.
If there is a reply, however, it will eventually lead to the following one: "The Bible says so, and I believe it on faith." So the discussion has arrived at a dead end.
The most anybody can hope to get from the topic is an agnostic-theist answer in which the theist confesses ignorance but maintains belief. "I don't really know whether natural laws can exist without the Bible God, but I believe they cannot."
And the non-believer, too, only has an agnostic-atheist answer but maintains a non-biblical position. "I don't really know whether natural laws can't can exist without a god, but I can't find any evidence for it."