May you all have peace!
What an intriguing question! And Bobsy is closest to the truth: Cain was in fear of the 'avenger' of death, which avenger was always a family member. Such one was OBLIGATEDt to go after the murderer and put him/her to death. That is why the 'cities of refuge' were later constructed for Israel. For Cain said, "Anyone FINDING me, will kill me" and Numbers 35:19 says of the avenger, "When he CHANCES upon him (the murderer) he himself will put him to death."
Someone also stated that there was no law in heaven. Actually, there WAS law in heaven... AND on earth. But such law was 'oral'... and not yet 'written'. Indeed, if there was no law, Satan COULD have became haughty and unrighteous with no consequence. And he COULD have 'misled' Adam and Eve, with no resultant cursing. If there was no law, then Adam and Eve COULD have eaten with no consequence. Cain COULD have killed Abel with no consequence. Joseph COULD have slept with Potphar's wife, Noah COULD be seen naked and Ham would not have had his son Canaan cursed, Moses could murder an Egyptian and not have to flee for his life. And so on and so on.
The PROBLEM was that Israel, when in the wilderness, couldn't KEEP the oral law. So, it had to be written. And they failed in keeping that, for the most past, too, although unlike Job and US... they were protected from Satan. HE was not 'in the wilderness' with them. They were being led by holy spirit and thus sinned on their own.
Dear ones, good AND bad DID exist before creation. In fact, when completing His creative days, my Father THEN said 'it was good'. Otherwise, Adam and Eve could not be 'like' God... KNOWING good and bad... for indeed GOD would not have known it.
With regard to the Sumerians, ACTUALLY Hebrews are direct descendants of the Sumerians. The garden of Eden was located in the Mesopotamian Valley, the greatest city and region of which was ... Sumer.
The name 'Sumer' is derived from 'Shemer'... for it was the land settled by the descendants of Shem. Shem went south into what is known as Babylonia. Japheth went southEAST and his descendants are those who are primarily mongloid or Asian/Indian. Ham, went southWEST, and his descendants are those who are primarily negroid or dark African.
The descendants of Shem, however, went directly south and from these derive those who are Shemite... or SEMITE (Semitic)... and from whom those that are angloid derive. That is why although appearing Mediterranean and Middle Eastern to some degree, many, if not MOST Jews... appear white.
Technically, then, Adam, Eve, Cain, Abel, Enoch... and all the way to Noah... were 'Sumerians'... as the land they hailed from later took on that name. Ararat, the mountain on which the Ark was said to have landed, is in the upper region of Mesopotamia, just above the north end of the valley. So, Noah didn't really 'float' that far. South of Ararat, in the center of the Mesopotamia Valley, at the point where the Tigris and Euphrates meet, is where the 'garden' of Eden first set down. Just south of THAT... is/was the land of Sumer.
I hope this helps and I bid you all peace!
A slave of Christ,
SJ