The Moral Argument for God

[Pat Mustard]

If there is no heaven, no hell and life ends at the grave, then does it really matter whether one chooses to live one's life as a Stalin or as a St. Francis? 

So your only options are to live as Georgian orthodox or Roman catholic? Somehow I don't think this is the argument you are trying to make.

Here's your argument from the other end: "Does it really matter if you live as if you were Terry Pratchett or Brendan Smyth?" It shows that religious people don't have a monopoly on morality.