I must stress that I do not want to make any quantifiable claims about genesis or similar such things. The central idea behind that (not I think that) lame example was that, events which we think are very very uncertain may have a sufficiently high probability of occurring at least once somewhere in the universe. Like abiogenesis happened right here on our earth! In Stephen Weinberg's words, 'We seem to have won a cosmic lottery!' The reason we think that they are unlikely to happen is because our brain is evolved to handle a certain time and length scale, the stuff beyond which is counter intuitive.
To elucidate that, we can think of two balls colliding with each other or a ball dropped from air hitting the ground. The Newtonian nature of the motion is something very familiar to our brain. At the same time, if we were to see a ball of a very large size where effects of space curvature are important, or a ball of very small size where the effects of Heisenberg's uncertainty are important we will be shocked out of our minds! (So were we, a hundred years ago) Scientific framework helps us overcome the bias of human intuition, and in my personal opinion is not just limited in explaining physical things. It in general has the potential to help us overcoming all sorts of limitations of human mind and make it freer in some sense.
In the same spirit of the above argument, a billion year old universe comprised of billions of galaxies is completely out of reach of a naive brain. Effort has to be made to understand it, similar effort has to be made to understand the beauty in Stravinsky. The people who really do not want to make this effort do think that earth was created 6000 years ago, and one is surprised to know the number of people who actually believe this in America. There are a large number of people who think that Man was created in the image of god. And I think that I can attribute that to the limitations of the imagination more than anything else. I must confess that I will have to justify this strongly.
Your point very well appreciated on a mind which requires a secure universe rather than a consistent one. But there are models of secure universe without a controller, and these models are pretty old. The Samkhyas, Jains, Bouddhas, the Legalists from China and some other eastern religions are all atheistic or in the least non-theistic and yet provide a highly stable, secure and moral universe. I will reserve my opinions on the Abraham's god for somewhere else. I want to say that that particular entity is not required even in a secure universe.
I suppose it is a very important question as both theist and atheist would agree that why do people need god in the first place and they would obviously offer different answers. Ranging from 'Everybody kneels before god's glory, Jesus Christ died for your sins' to 'Religion is useful for the powerful and hence they purposefully poison their subjects with it'. What science demands from us is to understand the process by which god has become so important for us as humans. And my previous post was a feeble and (sadly) polemic (and thus useless) effort towards that.
To conclude, one of the reasons I think supernatural is important for us is that we exist in this marvelous world, that is comprised of the earth, rain, beautiful birds and french wine! There doesn't seem any fathomable reason for it's existence. This reason is then attributed to the supernatural. According to me a very likely reason that we think that all this is too specific to have happened by chance is that we cannot comprehend the grandeur of the space-time in which this can take place where such events may cease to be unlikely.
Here's Karthik's response, it was too big to be continued in the comments section.
It is true that human imagination is truly limited. Even when steven spielberg makes a movie on aliens, he imagines them to be conveniently anthropomorphic. So I agree with that point of yours.
The genesis of life is something that is understandably more difficult. Even if we are able to reconcile the popping up of a replicator as a plausible probabilistic event at some point on the immensely large time co-ordinate there are definitely more complicated questions that creep up.
Why was natural selection favoured as a mechanism? How the hell did consciousness arise from nowhere? I believe we are not even close to answering these questions convincingly right now? It might probably require a bigger leap of imagination to explain consciousness than relativity or quantum mechanics.
But more importantly, I believe that it is possible for great leaps of imagination to be built on wrong premises. Newton's is one example that we're familiar with but no one in her right mind would say that he was deluded to think of a universe where time is absolute. Similarly, I find it reasonable to acknowledge personalities like Christ and Buddha; they were clearly mavericks who thought in a radically different manner considering the time that they lived. It must have been a truly original mind to conceive then, something as rudimentary as collective ethics and principles based on universal aspects of human nature. Nonetheless, like the case of Newton, these were done on incorrect premises (holy spirit, Abraham etc).
While Newton has been superseded by Einstein (who will in good time be superseded by someone else), Jesus and Muhammad refuse to give up their positions of vantage. This is clearly disappointing and I can understand your concern. But I have some reservations on the manner in which you put forth your arguments; they tend to get really polemical sometimes.
The situation that we live in is funny. I think every person (theist or atheist, scientist or not) would acknowledge your premise, that human imagination is terribly limited. The atheists and theists are separated by a big chasm that needs to be explored. What is contained in that chasm is still open to speculation While the theist clutches her holy book and looks up at the sky, the vanguards of science have, for the past four hundred years burrowed to great depths in this chasm and disinterred wonderful things - Fraunhofer lines, probability theory, quantum mechanics, high speed computation etc.
Our repertoire is indeed much more impressive than theirs but the chasm is still so big that it is difficult to get points across. With the natural human instinct to choose a world that bestows a sense of security and not bother about a sense of consistency, the choice for the mode of security becomes highly subjective-and religion is chosen by many over science.
I cannot comprehend why someone would outrightly reject the billion year old universe that we are a part of, where recorded human history is like a few grains of sand in a vast desert; a universe so vast that the light we intercept from different stars carries the sweat of events that happened a million years ago; a universe where a small planet has seen life evolve and consciousness thrive. It is more beautiful than can be found in any holy book!
The question as to what to do while we are confronted with this chasm, I guess it is a choice much like what Alice had to make :-).