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

[Belacqua]

I'd also note that you've added two conditions to the Thomastic "logic", by stipulating "comes to be" and "passes", neither of which are in there ... looks like more goalpasting to me.

These are characteristics of contingent things. Something that isn't contingent hasn't come to be, by definition. I suppose that a contingent thing might come to be and then never pass away, but I have never heard of such a thing. Certainly it would pass away if its essential cause ceased to exist -- that's also a definition of contingent.

 How do you know that any prime mover is immortal? Looks like another suitcase job in play here.

I don't know that, and the argument doesn't address that. Of course Christians say that God is immortal, but that's not in the present argument.

How do you know your godling didn't "come to be", or will not "pass away"? You cannot know either. That too is special pleading. It's also trying to be sneaky, which I don't really appreciate as it smacks of dishonesty.

The gist of the argument is that contingent things can only exist because there is one non-contingent thing. Normally we say that things which come to be have been caused by something else, but if you have a way of describing how something can come to be without relying on the existence of a prior thing, then that would be interesting to know. 

As a result of both premises being flawed, why should anyone be obligated to accept your conclusion?

You haven't shown that the premises are flawed.

You did two things:

1) disagreed with my characterization of contingent things as being impermanent. And I concede that something which is caused by something else may in fact exist as long as the cause continues to exist as well. 

2) added the idea that the First Cause must be immortal. That's something you could argue against, but it's not part of the Argument from Contingency which this thread is about.

You're clearly hell-bent on believing in Heaven, for reasons of your own.

None of the Five Ways addresses the issue of heaven, and I have not said anything about it, nor about what I'm hell-bent on.