Tower of Babel
The Tower of Babel is a myth in the book of Genesis. It tells the story of early humanity cooperating to build a tall tower. God disapproves of humans cooperating, so he confuses their languages.
"The Lord said, 'If as one people speaking the same language they have begun to do this, then nothing they plan to do will be impossible for them. Come, let us go down and confuse their language so they will not understand each other.'"
This means that God is opposed to cooperation, communication and human autonomy (which incidentally are core values of humanism). The traditional story that God disapproved of mankind's pride is not well supported by the text (although apologists tend to interpret autonomy as pride).  God's actions also tie into the Biblical message that knowledge is wrong.
There is no good linguistic or archaeological evidence to support the story, and again shows that the Bible is not a reliable historical source.
Mankind has since built far higher towers than would have been possible, with at least as much human autonomy, yet no divine intervention has occurred. God is not very consistent in dealing with humans.
Non-Biblical theories cannot account for language diversity
- "The idea that the language capacity could come about by chance more than once is even less likely than its evolving accidentally just once. No one has shown how language families as different as Proto-Indo-European and Proto-Sino-Tibetan could derive from a common source. The same holds for the other 92 families insofar as they have been studied."
Apart from being factually questionable, this is also an argument from ignorance.