In Genesis 11:1-9 Man sough to reach god by building a tower to the heavenly places. They were able to collaborate because they spoke in one tongue. Their sin was that they tried to reach Him by heir own power and ability. God confused their languages and dispersed them throughout the lands.

On the Day of Pentecost, God allowed all who gathered to hear in their own language so that He may bring them to Himself. By His power.

Genesis 11:1-6, Genesis 11:7, Genesis 11:8, Genesis 11:9, Acts 2:4, Acts 2:5, Acts 2:6, Acts 2:7-11 and Acts 2:12