I don't believe in any sort of a god, or supreme being, or flying spaghetti monster, and as a consequence I don't have any expectations or fear about what happens after I die.
Up till now I've always behaved ethically--in a socially responsible way, more or less--it's been convenient. However, it's more or less a habit, layered on early canalisation of moral training by religious parents.
Can you give me a reason for continuing to behave in an ethical fashion? Is there a compelling philosophical reason for being 'good'--assuming I'm not afraid of punishment, or don't expect to get caught?