The argument goes that invoking god as the creator of the universe does not actually solve the problem of creation, because in order to create a universe as complex as the one we observe, this deity would have to be at least as complex as our universe. Thus he would have had to have been created too, and the problem becomes recursive, with no solution in sight.
This is not a lame argument backed 'only by scientists' who are sometimes accused of not thinking deeply enough on the important subjects. (I feel a post on that topic to be imminent!) This argument of the creator god being recursive is supported by some of our greatest philosophers too. See the end of this post for more detail.
The question arose again recently when my friend and regular commenter, Hilary posed the question in a slightly different way.
"How come scientists often harp on about it being illogical for there to be a God because He Himself would have to have been created, yet are quite happy with the origins of life and of the Universe to have come from nowhere?"
This adds a slightly different spin, and it actually touches on two different topics.
First the creation of the universe might be explained by the multiverse theory. Quantum mechanics would allow this type of creation - especially of a universe like ours that appears to have exactly zero energy. I'm strangely uninterested in this although I know that many people have strong views. For me - suffice to say that is is perfectly possible that the universe came about this way. Call me a deist if you like, but that would be mis-representing the situation.
As for the origins of life - that is an entirely different and more interesting topic (for me, personally). I'm not sure why someone with a physical sciences degree should latterly find the biological sciences so exciting. I think it probably comes down to the genomics revolution that we are experiencing in our own lifetimes. This is the biological equivalent of the periodic table being developed, with the search for all the elements. The last two decades have converted the biological sciences from what appeared (to me as a school-boy) to be a systematical cataloguing process into a brand new exciting science. New discoveries every week make the biological sciences such a fertile ground for learning, whereas in physics and chemistry we wait for a long time to hear really exciting snippets of news.
To attempt to answer Hilary's question, it all comes down to complexity. The earliest life forms must have been very very simple self-replicating forms - hardly beings that were able to create a whole universe from nothing.
The process of evolution has turned those simple forms into much more complex creatures that we see around us today.
So there really is not a dilemma here.
Finally, to prove that it is not just scientists and other shallow thinkers who have considered the problem of 'First Cause', I can do no better than to quote one of the great thinkers of the 20th century, Bertrand Russell. In his essay - "Why I am not a Christian" he wrote:
The First Cause Argument
Perhaps the simplest and easiest to understand is the argument of the First Cause. It is maintained that everything we see in this world has a cause, and as you go back in the chain of causes further and further you must come to a First Cause, and to that First Cause you give the name of God. That argument, I suppose, does not carry very much weight nowadays, because, in the first place, cause is not quite what it used to be. The philosophers and the men of science have got going on cause, and it has not anything like the vitality that it used to have; but apart from that, you can see that the argument that there must be a First Cause is one that cannot have any validity. I may say that when I was a young man, and was debating these questions very seriously in my mind, I for a long time accepted the argument of the First Cause, until one day, at the age of eighteen, I read John Stuart Mill's Autobiography, and I there found this sentence: "My father taught me that the question, Who made me? cannot be answered, since it immediately suggests the further question, Who made God?" That very simple sentence showed me, as I still think, the fallacy in the argument of the First Cause. If everything must have a cause, then God must have a cause. If there can be anything without a cause, it may just as well be the world as God, so that there cannot be any validity in that argument. It is exactly of the same nature as the Hindu's view, that the world rested upon an elephant, and the elephant rested upon a tortoise; and when they said, "How about the tortoise?" the Indian said, "Suppose we change the subject." The argument is really no better than that. There is no reason why the world could not have come into being without a cause; nor, on the other hand, is there any reason why it should not have always existed. There is no reason to suppose that the world had a beginning at all. The idea that things must have a beginning is really due to the poverty of our imagination. Therefore, perhaps, I need not waste any more time upon the argument about the First Cause.