According to Genesis 11, God (speaking as a triune entity), when he observed that the people living on the earth had gathered together on the plain of Shinar (probably near ancient Babylon, in modern day Iraq) to build a tower to the heavens, resolved to go "down" to the earth and confuse (literally, "mix") their languages (literally, "lips").  Why would God do such a thing?  Why would God not want humans to speak the same language?  Why would he not want people to understand each other?
     Consider the context.  After the fall (Genesis 3), any hope of humanity getting along with itself had vanished.  And after the flood, as Genesis 10 makes clear, humanity began to migrate and diversify, spreading throughout the world, rippling into many, many different tribes and nations, and developing just as many, if not more, different languages.  Though the people in the plain of Shinar were together in intention and speech, even if God had not confused their language, they would have split eventually apart anyway:  a fallen humanity cannot keep itself in constant comraderie and unity.  God knew what had come before and, more importantly, what would yet occur as human history began to play itself out across the landscapes of the planet.  He knew that diversity, though inevitable and entirely human, was, at that time, a reflection, not of divine design, but an unplanned and unconsidered product of human sin.
     But all was not lost.  Think about the day of Pentecost, the day when, by the power of the Holy Spirit, the people who were gathered in a room in Jerusalem began to speak in a multiplicity of languages, languages from all over the known world and, amazingly enough, regardless of the language, could all understand each other.  In an odd sort of way, diversity had now become oneness.  Diversity was now design!  What was God doing?
     What God was doing, in this instance was to, after seeing and grieving over millennia of human fracturing and antimony, in the person and work of his son Jesus, bring the diversity of his human creations back together.  He was bringing people into a new community, a new gathering, a new assembly of life, love, and unity under the heavens.  In the advent of his Son, God was transforming diversity and difference and linguistic variation from points and results of contention and friction into pillars of a community that lauds and celebrates them as visible expressions of the creativity of God.  In the reconciling work of Christ, God ensured that diversity and difference would become, not the random outgrowth of fallenness and sin, but the fully ordained and truest picture of whom God made people to be:  nearly infinite variations, conformed to the image of Jesus Christ and bound in eternal community, of the generative work of a God who desires for them to be with him forever.