Pre-Judaic cultures were well aware that lying, cheating, stealing, not keeping one's word, etc. ..were WRONG, and they didn't need a formal, monotheistic religion to confirm this for them. And in today's world, atheists are no more or less likely to act unethically than people who are formal members of a religion. Well, well... Let's take a look at these "pre-judaic" peoples...
Genesis "6:1 Now it came about, when men began to multiply on the face of the land, and daughters were born to them," ... 6:5 Then the LORD saw that the wickedness of man was great on the earth, and that every intent of the thoughts of his heart was only evil continually.
Wow, looks like we have a bunch of natural born "do-gooders". LOL!
Those not familiar with the rest of Genesis Chapter 6, all those natural born "do-gooders" were wiped off the face of the earth by the Flood.