Perhaps your sentiments lie with Karl Popper. Religion, argued the great philosopher of science, lies in the realms of metaphysics and is not open to scientific enquiry. That is the line most biologists take to justify sidestepping the issue. But there is no denying that religion and gods are a core part of human behaviour. That's why I and a growing number of biologists think we must offer some insight into the questions of why religion exists and at what point in human evolution it began.
Humans exhibit one feature that is very odd by animal standards, namely our extraordinary willingness to accept the will of the community and even to die for it. This level of altruism is the key to our success, allowing us to exploit cooperative solutions to the problems of individual survival and reproduction. For these to work, however, the individual has to be prepared to trade immediate personal interests for long-term gains. And high levels of group conformity expose us to the risk of free riders - those who take the benefits of sociality but will not pay the costs.
Of course, we can and do control free riders with policing and appeals to decency. But in the end, both strategies carry only so much weight: who cares if you don't like what I do if I gain enough by doing it. Religion offers a significant advance because the threat of intervention by forces beyond our control - whether now or after death - offers a level of penalty that far exceeds anything the civil estate can manage. But it only works if people believe in the existence of a shared supernatural world.
That's where our species' special talent for mind reading comes in. This phenomenon is best known in the form of "theory of mind": the ability to understand that someone else has a mind driven by belief-states. This might be represented in the sentence: "I believe that you suppose that there is a supernatural being who understands that you and I want to aspire to behave decently." It is this kind of thinking that enables us to go beyond holding personal supernatural beliefs to organising religion as a shared, social phenomenon.
So, our brains allow us to create gods and religions. But is this ability simply an accidental product of the evolution of big brains, or is it an adaptation? My own studies show that in primates, including humans, the volume of the neocortex - and especially the frontal lobe - is directly correlated with group size and social skills. In other words, the evolution of brain size has been driven by the need to provide the computational capacity to support the social skills needed to maintain stability among large groups. And in the case of humans, these social adaptations include religion.
By recognising that religion requires a large amount of mental power, we can also start to ask when it might have evolved. Plotting theory of mind abilities as a function of brain size in our fossil lineage suggests that the complexity required to support religion is likely to have arisen very late in our evolutionary history. It could not have happened before the appearance of Homo sapiens half a million years ago, and possibly not until anatomically modern humans appeared 200,000 years ago. That tallies with evidence for the evolution of language, another prerequisite for religion.
Of course, religion isn't all stick and no carrot. While religious sanctions help enforce conformity, religious experiences make us feel part of the group. Once again, evolution seems to have furnished us with mental mechanisms that make this possible. In recent years neuroscience has revealed the so-called God-spot - part of the brain's left parietal lobe, responsible for our sense of spatial self - an area that shuts down when individuals experience ecstatic states (New Scientist, 21 April 2001, p 24). As well as being linked with a sense of "oneness with the universe", it also creates the blinding flash of light associated with trances and religious experiences.
But perhaps the most powerful device for reinforcing commitment to the group must be endorphins. These brain chemicals are released when the body is under stress. It's surely no coincidence that most religions involve practices such as flagellation or long periods spent singing or dancing, which trigger a flood of endorphins whose opiate-like effects make us feel relaxed and at peace with those we share the experience with.
So, gods are created by big brains to prevent free riders benefiting from cooperative society without paying the costs. But religious experience can also be seen in a more positive light, as a way to help reinforce the group's effectiveness as a bulwark against the vagaries of the natural world.