Wow article on the proof of God, which ends with this amazing quotation from Thomas Nagel. But, check out the entire article, please. I cannot reproduce it all here, but it is thought-provoking. And, the Rabbi has read Feser.
The theological philosopher Edward Feser has done a great job explaining this facet of the argument (and the argument as a whole) in his book "The Last Superstition." By way of analogy, he has the reader envision a hand which is holding a stick which is pushing a stone. Would it be accurate to suggest that the stick is pushing the stone? Not really, as the hand is doing the pushing. But what allows the hand to push in the first place? The arm, which in turn is dependent on the muscles which are dependent on cells which are dependent on molecular structure which is dependent on atomic structure which is dependent on the primary forces of gravitation, electro-magnetism and the weak and strong nuclear forces which are dependent on ... what? What we'll see is that even if there were an infinite series of contingent causes such as these, we would still need a final, un-caused cause to get the ball rolling. Without it, nothing could unfold as nothing would have started the process.
I speak from experience, being strongly subject to this fear myself: I want atheism to be true and am made uneasy by the fact that some of the most intelligent and well-informed people I know are religious believers. It isn't just that I don't believe in God and, naturally, hope that I am right in my belief. It's that I hope there is no God! I don't want there to be a God; I don't want the universe to be like that. Thomas Nagel