Genesis 11

The people were given a commandment- scatter and fill the earth. The plan that they had was contrary to God's command. They thought they could settle in one place, all be together, and take it easy. The tower they were building was an attempt to bring God down to their level. When God said "nothing they plan to do will be impossible for them" does not mean that they would become equals to God and really be able to do anything. Rather- working together there would be no extent to what their pride and selfish desires would bring about- they would together go against God's good plans. In truth, what God did was to their benefit even if they did not know it because God's commands are based on perfect wisdom and love. Can you imagine how it must have been when one day you talk to your friend and the next day you cannot understand a word they are say?