I've heard this argument before. It's an interesting probability statistic, no doubt.

By no means do I desire to argue against your beliefs, but I would like to present a response.

My first point, there has been evidence gathered that life likely started from RNA and then evolved into DNA. RNA only has 300 base pairs, this significantly reduces the number of possibilities. Just like DNA, RNA is also made up of 4 different codons which creates a 4^300 probability calculation. This still would take longer to assemble by chance than the 13 billions years since the "big bang".

My second point, the problem with this calculation is that is over simplified and doesn't represent the current theory on the origins of life from a science perspective. It assumes that a single, unique RNA was assembled that life sprung forth from. Instead, it's more likely that many, many RNA strands were created and evolved together through a ligation reaction at a molecular level to be more likely to generate the catalyst that sparked life. Not only is this more likely, it has been scientifically tested and the results, although not conclusive, are reproducible and do support the theory.

By re-examining this with RNA replacing DNA AND assuming that evolution began even before life began and that RNA polymers evolved to be more likely to catlyze life we come to a calculation that would pass the smell test even in Statistics 101.

http://www.science20.com/stars_planets_life/calculating_odds_life_could_begin_chance