It wouldn't be an argument for atheism per se, but let me have a shot (I'm Christian). If there's no higher being the only thing that is important is the personal well being and continued survival of the individual (or if we want to go on a smaller scale the cells, genes etc.). That would mean that anyone who has the least things holding them back, be it morals, tradition etc. would be able to compete better - see high functioning psychopaths that manage to fit in society and play the system (be it societal or personal). So basically people who are not bound by morality are able to utilize their abilities to a higher degree and live a better life. Now, that sounds like übermensch, Nietzsche like philosophy ... or Nazi philosophy, but it is the closest I could get. Basically: 1: There's no God or any higher being. 2: There is no anchor for morality, right and wrong. 3: Since there is no morality the universe only works on the strict survival of the fittest, evolutionary law. 4: People who can utilize their abilities are much better at getting the necessary resources needed for their survival. 5: Atheists are more fit to survive. That said, if I believed this, I wouldn't want people to be atheists, as that would increase my competition (see hawk and dove game in game theory)