The Principle of Contingent Causation: The Impossibility of Infinite Regress.

[Belacqua]

Go back and reread what he wrote. He quite literally wrote "In other words, at least One Being in Existence exists non-contingently" (bold added). If he's not stating the argument right by your view, take that up with him, 'cause it ain't my problem. I'm answering his argument directly, and pointing out that he's trying to smuggle a being in arbitrarily.

Yes, it's a persistent language problem. I also think that a lot of Christians should be more careful about this. 

Our thinking is structured largely by the language we use. Unfortunately English concepts often don't map well onto Aristotelian or Thomist ones. So there is always a danger of confusion concerning "a being" or "an entity," as well as, as I mentioned, "cause." 

(For example, Japanese has different nouns for a tangible thing and an intangible thing. So from the start it's generally clear what kind of "thing" we're talking about -- in some cases it's clearer than English. There is also a rich vocabulary for philosophy in this vein, addressing materiality and ideality. All this is inherited from Buddhist thought.)

It's the sort of thing that people can work out. When both sides are friendly and open-minded, we can ask for clearer definitions and make things clearer. I understand that's not a very common state for conversations.

He needs to demonstrate that this could not possibly be a process and must be a being (complete with capital B!), and then he need to justify jumping from a creative being to his particular godling.

Let me go get some popcorn. He's gonna need a bigger boat.

Yes, the argument in the OP is far from complete or persuasive as it stands. It is one part of a systematic theology. 

For example all of the Five Ways hold that infinite regress is impossible, but don't explain that within the argument itself. That's why I always say that none of them is a self-contained argument, but more like a syllabus for a semester-long college class. Each step of the argument has prerequisites. Of course Aristotle and Thomas Aquinas have elaborate arguments as to why infinite regress isn't possible. 

So again, in a friendly conversation we can certainly ask "wait a minute, why isn't infinite regress possible?" and then ideally that could be explained also -- and rebutted and discussed. 

And as I said before, none of the Five Ways addresses why a First Cause is "his particular godling." That calls for several further arguments.

As you say, it needs a big boat. 

I don't know if the OP is willing to go to those lengths, or if he's aware of the prerequisites we'd need to find his argument sensible. Often I try to discuss these things with people and they seem unwilling to have a conversation.