Those who advocate the postmodern view of the world (that we construct our world through our language within our separate communities) do so in part because they believe it will be a remedy for violence in the world.  If we would only understand that our views are merely the views of our community and not representative of reality itself (i.e., if we didn't have confidence that we had the "right" view), then (they believe) we would be humble about our views and just live and let live, not attempting to force them on others through violence.

Here's the irony, however:  this view will, in the end, lead to more violence than we currently experience.  Imagine a world where all people in all societies view that world in postmodern terms:  all of their values and stories about the world (history, theology, etc.) are created through the languages of their particular communities.  Further, communication of one's beliefs to another who is part of a different community is not possible in any meaningful way because the separate communities (e.g., Christians and atheists) have different languages and have constructed different worlds for themselves.  The only way for someone outside the community to enter in is to slowly learn the language and behavior of that new community. 

Why do I say this will lead to violence?  Currently, people from different communities (like Christians and atheists) debate and discuss their diverse ideas in an effort to promote what they consider to be the truth.  But imagine what would happen if the whole world believed in the postmodern view described above.  The problem begins with this:  even if people do not believe their view represents actual reality, being a postmodernist does not automatically make people care less about the view they prefer.  After all, postmodern philosophers and theologians prefer their views strongly enough to write many books trying to convince others to take on those views as well.  The danger then comes because of the isolating effects of the postmodern view.  Each community is trapped within the confines of its own language, and the people within are unable (or believe they are unable) to rationally communicate with those outside (who have very different languages) to persuade them that their view is a better one.  That is what will lead to violence.  In a world where postmodernism dominates and people live out the implications consistently, what is left when separate communities come into conflict and the members believe rational communication and persuasion is impossible?  Only the international language of power remains.

[Note:  As Andrew rightly pointed out in the comments section, though I used the general term "postmodernism," not all who call themselves postmodernists hold to the precise view I described.  In this post, I refer only to those who believe we are "inside" the language of our community, that our language constructs our world, etc.]