Sin before Moses

Romans 5:13-14 shows that the Law existed and applied to the whole world before it was given at Mt Sinai.

...for sin indeed was in the world before the law was given, but sin is not counted where there is no law. Yet death reigned from Adam to Moses, even over those whose sinning was not like the transgression of Adam, who was a type of the one who was to come.
Romans 5:13-14 ESV