In his debate with his fellow Oxford professor, John Lennox, Richard Dawkins objected to the idea that the beginning of the universe provided evidence for the existence of God. Dawkins’ argument was that the Bible, in claiming that the universe had a beginning, had a 50% chance of getting it right – you might as well toss a coin. In his book The God Delusion, Dawkins presents two further objections. The first is that if there is a cause of the universe, there is no reason to think that the cause would have all the properties attributed to God such as omnipotence, omniscience, the ability to listen to prayers and forgive sins, etc. Related to this, a further objection is that it ‘would be more parsimonious to conjure up, say, a “big bang singularity”, or some other physical concept as yet unknown.’ 
In responding to Dawkins’ objections, I will not argue that the universe had a beginning, but will address the question of whether such a beginning would count in favour of God. Let’s take his objections in reverse order. If the universe had a beginning, would a big bang singularity be a better candidate for being the cause of the universe than God? Dawkins’ suggestion seems confused. A big bang singularity represents a problem, not a solution, for Dawkins. What the exact nature of such a singularity would be is far from clear, but if the universe had a beginning such a singularity would mark the beginning (or else the time immediately after which the universe began to exist). If we consider the timeline of the universe, the singularity would simply be the time t=0.
There are at least two problems with appealing to a singularity as the cause of the universe. Some have argued that a big bang singularity is precisely nothing, which still leaves us with the question of how the universe came into existence out of nothing. Others have argued that a big bang singularity would be a real physical state, but if so it would still just exist at the time t=0. So the question would be how did the singularity come into existence out of nothing? Cosmologists John Barrow and Frank Tipler put it like this, ‘At this singularity, space and time came into existence; literally nothing existed before the singularity, so, if the Universe originated in such a singularity, we would truly have a creation ex nihilo.’ 
Now consider Dawkins’ objection that there is no reason to think that the cause would have all the properties attributed to God. The obvious response is ‘so what?’ The point of the argument is not to establish all the attributes of God. Just because it cannot tell us everything about God, it does not follow that it cannot tell us anything about God. Dawkins would not be impressed by an objection to evolution on the grounds that because it cannot tell us everything about the history of life on Earth it cannot tell us anything. In the current context, the basic idea is just that if the universe had a beginning, it must have a cause that is not physical and that is outside space and time. That is certainly much more consistent with belief in God than it is with the materialistic atheism espoused by Dawkins.
Finally, what about Dawkins’ quip that there is a 50% chance of getting it right about a beginning? This is the weakest objection of all. His idea is that since there is a 50% chance of getting it right, it isn’t very impressive and so it doesn’t count much in favour of theism. But this is an incorrect approach to evidence and probability. Let’s consider an analogy. Suppose Jones is a suspect in a murder case and that traces of the victim’s blood are found on his clothing. We need to ask two questions. First, what are the chances of the victim’s blood being on Jones’ clothing if he committed the murder? It’s difficult to say. It certainly isn’t inevitable that it would have happened, but it doesn’t seem all that unlikely either. Let’s say it’s a 50% chance just for the sake of argument. Second, what are the chances of the victim’s blood being on Jones’ clothing if he didn’t commit the murder? This seems very unlikely indeed. 1 in a million would seem much too high. And it is the contrast between the 50% chance and the 1 in a million chance that makes the evidence of the blood stains so powerful.
So in the case of the universe having had a beginning we need to ask two questions. First, what are the chances of the universe having a beginning if there is a God? Second, what are the chances of it having a beginning if there is no God? With the first question it’s hard to say. Would it be likely that the universe would have had beginning if God exists? It certainly doesn’t seem unreasonable to think so but, perhaps surprisingly, some believers in God have thought that it did not have a beginning. Let’s say that there is a 50% chance. The second question seems much easier to answer. It seems very unlikely indeed that the universe would have a beginning if there is no God. How could the universe just pop into existence out of literally nothing without a cause? This is why many atheists have sought to avoid evidence for the beginning of the universe. As Stephen Hawking puts it, ‘Many people do not like the idea that time has a beginning, probably because it smacks of divine intervention.’ 
So what are the chances of a beginning without God? It could certainly be argued that there is no chance at all, but let’s be extremely generous and say it is 1 in a 1000 (0.1%). If you start out thinking that the existence of God is quite unlikely (10% chance), then a beginning to the universe would make it almost certain that God exists (98%). So in fact, a beginning to the universe would provide very impressive evidence for the existence of God.
I haven’t tried to show here that the universe actually had a beginning, but if there is evidence for a beginning as many scientists believe would it provide evidence for God? Dawkins has offered some objections to this idea, but as we have seen they are very weak indeed.
 A further objection is based on the idea that God’s existence would also need an explanation. Dawkins seems to leave open the possibility that there is a physical cause to the universe and that this cause also had a cause, and so on, the whole way back, so there is no first cause. Issues are along these lines are considered in the article The Evidence for God: the Universe.
 Richard Dawkins, The God Delusion (London: Bantam, 2006), p. 78.
 I have looked at some of evidence in Atheism’s New Clothes (Nottingham: Apollos, 2012), chapter 4. For a more detailed study see William Lane Craig and James D. Sinclair, ‘The Kalām Cosmological Argument’, in William Lane Craig and J. P. Moreland (eds.), Blackwell Companion to Natural Theology (Chichester: Wiley-Blackwell, 2009), pp. 101–201.
 As for Dawkins’ appeal to ‘some other physical concept as yet unknown’, this involves rejecting the idea that universe had a beginning since only in that case could there be any physical processes.
 John Barrow and Frank Tipler, The Anthropic Cosmological Principle (Oxford: Oxford University Press, 1986), p. 442.
 Interestingly, William Lane Craig argues that in addition to transcending space and time the cause must be changeless, immaterial, without beginning, uncaused, unimaginably powerful and personal (‘In Defence of Theistic Arguments’, in R. Stewart (ed.), The Future of Atheism: Alister McGrath and Daniel Dennett in Dialogue [London: SPCK, 2008], pp. 77-78).
 Stephen W. Hawking, A Brief History of Time (London: Bantam, 1988), p. 46.