First they exalt agnosticism as though it is a godly virtue - mystery, ambiguity, and uncertainty as forms of piety. This indeed is a clever disguise because then the truth that God has revealed can be treated as though it has been concealed. But - "The secret things belong to the Lord our God, but the things revealed belong to us" (Deuteronomy 29:29). Then as soon as a Christian deals in truth or certainty, speaking a clear, "Thus says the Lord," he or she is caricatured as immodest, arrogant, Pope-ish, omniscient, excathedra speaking, pontificators of doctrinaire arrogance. Why? Because of the postmodern's hatred for absolute truth.
Phil Johnson of PyroManiacs said, "Like all good postmodernists, Emergent Christians hate clarity and precision. They despise authority, and they detest certainty. They say they don’t want answers; they want mystery. They don’t want to be preached to; they want a conversation. They don’t want to have to judge whether something is orthodox or heretical, true or false; they want to create their own spiritual reality, and they want to be affirmed while they do it. Unfortunately, the evangelical movement has plenty of people who are willing to affirm all of those things." (Source)
Another clever disguise used by postmoderns to appear that they don't really hate truth is their never ending trumpeting of thier diversity. This is in order to attempt to make an accurate portrait of the movement appear to be just a caricature and therefore critique-resistant. As Dan Philips said in one post comment box, "Try to nail down one blop of EC Jello, and another blop says "I'm not that way!" (Source)
So as soon as you describe an accurate portrait of what postmoderns are like - haters of truth, clarity, certainty, and despisers of authority, one will come along and say, "I love absolute truth and we're not all that way. It's unfair for you to lump us all together that way." However, keep engaging him or her in conversation and you will sure enough discover that they fit the portrait and still want to call it a caricature.
A caricature is a picture or description ludicrously exaggerating the peculiarities or defects of a person or thing (Websters Universal College Dictionary). It is an untrue, ridiculous, and absurd characterization. A portrait does not involve ludicrous exaggerations but is an actual and true portrayal or depiction of a person or thing.
Beware of the caricatures painted by postmoderns and study closely the portrait of apostates as revealed in God's Word.
Edit: John Piper has an excellent post today concerning mystery. Check it out here