Why do you not believe in God?

[CliveStaples]

lol,
very good self refutation on the last line.
If THE CAUSE began to exist it would be x.
The argument is question begging because you are not trying to prove that the universe has A CAUSE, but that the universe has THE CAUSE.
You cannot use the thing you attempting to prove in your premise. You arrive at a self contained circular mambo jumbo.

But the argument doesn't assert that THE CAUSE doesn't have a cause.

Remember, it's:

(1) For all x in X, Q(x).
(2) y is in X.
(3) Therefore, Q(y).

Now, maybe the cause of y, let's call it c, is also in X. Then you'd have Q©. Where's the contradiction? It isn't circular reasoning; neither Q© nor ~Q© was assumed in (1) or (2); neither was Q(y).