If God can exist without being created by something, why can't the universe?
The argument I've heard is "It must stop somewhere, and whatever it stops at, we'll call that god". It's not a good argument, because it then hopes that you conflate the Judeo-Christian deity with that label and make a whole bunch of assumptions.
It's often paired with woo that falls down to simply asking "Why?", such as "Nothing could possibly be simpler than my deity"
What is this stop business? I have it on good authority that it's turtles all the way down.
So if it stops at the universe, the universe itself is called 'God'?
Yeah exactly, though then you'd generally get arguments pushing you towards "But it's actually totes Jesus".
Not my argument but causality is a principle of the universe and may not be applicable to entities which exist outside of it.
The universe is bound by physical rules but something which exists outside of it may not be. Of course this is pure conjecture but you can find interesting theological arguments beyond creationists.
Via a difficult method you observe something strange.
For conversation's sake you call what you observed, "gob".
Overhearing the conversation, people, who never practiced the method (because it is difficult), discuss "gob".
In time the method is forgotten. But the discussion continues.
That baseless, insubstantial discussion.