How soon after the flood did humanity fall back into rebellion?
Within about 200 years after the flood, the offspring of Noah's three sons fell into total rebellion and ignorance of God's offer of salvation. They tried to approach heaven through their own false worship, leading to the Tower of Babel. This shows how quickly humanity turned from God's provision.
Les explains that after the flood, God started over with Noah and his three sons, but within 200 years their offspring were again in total rebellion. They were in total ignorance of God's offer of salvation and tried to make their own way, attempting to approach heaven through their own false worship, which resulted in the Tower of Babel. He also notes that the flood occurred 400 years before Abraham, and Babel came about halfway in between, using round figures.