Atheists should always behave ethically. Atheists need to behave ethically.
Would you like to know why?
Atheists should always behave ethically – they need to behave ethically – because, as atheists, they do not have God on their side.
Conversely, religious people do have God on their side.
With God on their side, religious people do not need to behave ethically. They can kill and maim and steal and pillage and rape, all in God’s name. It must be great to have God on your side.
They can even kill each other, for not believing in God just the right way. Christians can kill Muslims and Jews cankill Zoroastrians or whoever they want, because they have God on their side.
Boy, atheists must sure be stupid. If they had God on their side, they wouldn’t need to be ethical at all.
(What can I say? I have fun.)