In the thread "Your purpose in Life", in response to my asking why does God not require a creator FMJ wrote:
Everything that has a beginning requires a cause, God is infinite and requires no cause.
First off, it is not absolutely clear that the universe had a beginning. The Big Bang theory essentially refers to the period of cosmic inflation at the very beginning of time. The standard interpretation is that what preceded this was the moment of creation with a problematic claim that it was due to a quantum fluctuation. The objection to that is a fluctuation in what exactly? One feature of cosmic inflation is that it eliminates any trace of what the earlier epoch was like. One possibility is that it was the end of an old epoch in the universe and that the universe is actually infinitely old (and by your argument causeless) with periodic inflationary expansion. So it is not necessarily the case that the universe had a beginning.
Suppose however that it did. With no laws of physics to constrain what can happen before the universe started to exist there is no particular objection to anything and everything happening. So there is nothing to stop a universe with our laws of physics just popping into existence.
Cause and effect are problematic concepts in fundamental physics. There is no physics theory that establishes what cause and effect are. Essentially if there are two events and one precedes the other and the other would not have happened without the former we say that the former caused the latter. However, we do not really have a right to claim that the latter event would not have happened. Our intuition is based on macroscopic phenomena. At a microscopic level things happen because they can, and what can happen is determined by various conservation laws. There is no event that causes a nuclear decay except the formation of the radioactive nucleus. Radio-active decay just happens basically because it can. So I disagree that "anything with a beginning must have a cause.", at least with regard to universes.
A typical argument against an infinitely old universe is that with an infinite amount of time having had to elapse before we could reach the present, time would never have reached now so the universe must have a finite age. This is a necessary step in arguing for a creator as one has to establish that there was a point of creation. It seems to me that this must apply to God as well. If God is infinitely old then he would never have got round to creating the universe. So the same problem exists for God.