Hi edsheppa! The above statement reduces morality to utility. Yet the moral law requires us to "do the right thing," regardless of utilitarian considerations. In a nutshell: The moral law says it is better to do the right thing even if it costs us, than to do the wrong thing and benefit from the wrong. Selfish people will tend to act for their own benefit regardless of considerations of how others may be harmed by their actions. Such behavior is justly condemned as immoral. A good and just society must condemn such behavior or the society would not long remain either good or just.
If you'll recall, the original claim was that atheists can give no rationally coherent and consistent account of their morality. Well, I think I have done so but it will ever be admitted.