Good point by commenter over at Ilion's:
One 'trick' I'm particularly tired of is this: "Atheists are just as moral as theists, so you theists better say this if you want any dialogue with atheists." Except A) Who wants dialogue with atheists, particularly New Atheists who are bound by politics more than anything? And B) On what grounds do I say atheists are as moral as theists? My stock reply is, oh, so atheists are typically against abortion, gay marriage, premarital sex, and other things I view as immoral? And that usually seems to shut down that move, if only for that particular moment.
Indeed. And if the atheist manages to get those ones right, there is still the question of "Good according to whom?"
Atheists are--by definition--in violation of the Greatest Commandment, after all, no matter how well they do at the Second greatest commandment.