From the Bible passages Genesis 11 and Acts 2, Tim talks about the power of common language and of clear communication, leading to technological progress. This has lead to much of mankind not having to struggle just to feed themselves and their families, but being able to research, to build, to diversify.
The great pitfall of this progress can be an arrogant affirmation of mankind's self sufficiency and a reliance on self.
However mankind still seeks for meaning and purpose beyond the physical, in the realm of the transcendent.
Pentecost trumps Babel, igniting a new fire amongst humans, the fire of the Holy Spirit in salvation and a new experience of God's destiny for us.