Can an atheist be ethical like theists

[Anomalocaris]

You've got to look at two possible scenarios:
1) You break some agreed upon taboo and your community beats the shit out of  you.
2) You break some agreed upon taboo and God beats the shit out of you. 
Unfortunately He is unable to punish you directly so He calls upon your community to beat the shit out of you.

The two situations are identical except for the unproven claim of the supernatural in the second.
Why is this so difficult for theists to comprehend?

Well it is not but when u r an atheist and ur community is not it can do that but when th whole community is believing that there is no god so where would these laws come from.
Let me give u an example if we are the society and we all agree here as people of that society that doing drugs is a personal choice then there will be a law permitting that.

And if we all agree that robbing a bad person isn't a bad thing then we legitimize too.

And if we all agree that incest is a personal matter then we will legitimize it too.

And if we all agree that relegion is a disease we will eliminate all relegious people from our society because it is the law like what happened in china and Tibet.

So you see my point here it is all a matter of agreement of the majority. And the majority aren't always right .

By example the majority of people elected Hitler in germany.

By example the religion of Islam caused IS to cut off heads and smash collective patrimony of humans civilization, in the 21st century.

Democracy beat hitler.  Is Islam going to beat itself?