I can't resist responding to one thing that Prof. Stairs says in his excellent reply: "If there's no such [necessary] being, then it might be that there's no explanation for why contingent things exist." I used to think that myself. But as I thought more about the question "Why do any contingent things exist?" I concluded that the question has a very simple answer -- indeed, many simple answers -- if it's a well-posed question in the first place, and those answers have nothing to do with any necessary being. I try to explain why in this paper.
The big bang theory says that time began with the big bang. Is that correct? Then does that mean that those who describe the big bang theory as an idea that something comes from nothing are incorrect? If time began with the big bang doesn't that mean there never was a time when there was nothing?