Noah: The Tower of Babel - What was the big deal? 

Adapted from the Bar Mitzvah sermon of Michael Simha

1. The Midrash says that the people at the time  were trying to rebel against G-d. When the Torah says that they were trying to build a tower that would reach up to the skies it could be interpreted as meaning they were trying to make a tower that would be so tall that if the flood would return, they would be saved. King Nimrod had assured them that the flood would come again. They would be ready. They would not have to deal with the wrath of G-d. They could artificially protect themselves from G-d's punishments. 

2. Rashbam says the sin was that they were trying to all live in one place. What is the sin with that? There are two reasons why that may have been a sin. One is that a disaster could wipe out the whole human race and another is that one of the first laws given to us by G-d was to fill up the earth and conquer every part of it. Ralbag explains that the reason G-d wishes for the world to be spread out is that this way the human race is guaranteed survival. Should natural disaster occur in one place, the other area would be spared. 

3. Rabbi Yitzchack Arama writes that they viewed technology as an end instead of a means, meaning that they weren't trying to build a tower for any reason other than the fact that they thought it would be nice to have a tall tower. 

4. Rav Meidan of Israel says that the sin was in trying to live in the city as opposed to the country. Cities are often  places of evil and dehumanization. The tower was a plan to ‘citify’ everyone.