What was pre-flood civilization like before human government was established?
Before human government, the pre-flood civilization had no law and no government, yet it experienced a tremendous increase in population. Its outcomes are seen in Genesis 6. Later, after the flood, God instituted governmental authority, including the right to execute a murderer, because man was made in God's image.
Les explains that the pre-flood civilization had no law and no government, yet there was a tremendous increase in population. The results of that condition are seen in Genesis chapter 6. He then presents the post-flood instruction about blood and murder as a progression: now, under governmental authority, man has the right to put a murderer to death, because God made man in His own image. Les also notes that later, about halfway between Noah and the call of Abraham, the Tower of Babel arose, where people rebelled against God's instructions and pagan religions began.