Piggy, excuse me if I missed this, but it is a long thread with a lot of side discussions.
What is your response to the theistic argument that a powerful God started the universe and then stepped away?
My response is "What, exactly, are you saying started the universe then stepped away, and into where?"
That apparent definition of God actually isn't a definition at all. It attributes no qualities to God. And no meaningful claims may be made regarding utterly undefined entities.
You state in the opening post "not only that God does not exist, but that God cannot exist."
Why is it the God described above cannot exist?
It cannot exist because claims for the existence of entirely undefined entities are non-claims.
If I say a woogle created the universe, then demand that you must admit that this woogle might exist, but refuse to say what this universe-creating woogle might be, I'm being ridiculous, because there's nothing for you to believe.
It is reasonable for you to dismiss my apparent claim as a non-claim, and unreasonable for me to attempt to insist, on the basis of what I've said, that you must concede that this woogle might be real.
You're left asking, "believe that
what might be real?"
The reason that I believe God cannot exist is that all the justifications for God have been debunked, and all the remaining explanations attempting to prop God up are either non-sensical, empty, humpty-dumptyism, meaningless, or contrary to fact.
I adopted a strong atheist position when I had considered the available possibilities thoroughly enough that I could say with confidence that all possible categories of justification must fall into one of those errors, as I've explained earlier in this thread.
So far, no one on this thread, on this forum, or who I've ever met or read has provided one that does not, or been able to explain how any definition of God could avoid one or more of those errors.