Noah was a righteous man and blameless in his generation, but his children began to stray from their father's path. Because of the flood, Shem, Ham, and Japheth were told to spread abroad and multiply in the earth. Instead, their descendants gathered and attempted to make a 'name' for themselves at Babel. The god of the nations have their origin in the fallen status of the sons of gods. We see that God gives people up to what they want but is very slow to give them up forever.