Postmodernism sounded so bad for Christianity that Christians forgot to notice how bad modernism is for it. You will find some of the lies of modernism in the purpose-driven church, but they were assembled further back than that. "Traditional" (50's America) -style churches pride themselves on being different than Medieval churches and anti-postmodern (especially anti-relativist and anti-purpose-driven), however they have some things strikingly-familiar to Medieval churches and purpose-driven churches, and have missed some major benefits of the postmodern movement (despite that those benefits are diamonds among rough postmodernism). A Christian can benefit from being postmodern in a Romans 14 way, while avoiding being so in an Isaiah 53:6 way, as long as one accepts that there can be an accurate map of reality (complete enough to guide someone to true unity with the living Messiah). However, in all this, what is normally missed is that modernism is just as dangerous to Christianity. After thorough experience and conversation guided by the Holy Spirit (as opposed to thorough research and guidance by scholarly precedent, which would be modernism's way), I have identified these lies in modernism that are also used by European-style churches (now primarily in North America):

Lie: we must respect and base our search for truth on the findings of previous scholars
Lie: there is no reason to question methods that produce predictable results
Lie: "good" results are results that can be measured
Lie: we can expect to live by the same methods that produced "good" results in the past
Lie: higher education and scholarly research (based on precedent) is the only reliable path to determine truth
Lie: case studies (truths gathered from experientialism) are unreliable and lead to error
Lie: adding more routine is important when the group begins to deviate from predefined goals
Lie: mechanisms or organizations that are bigger and less-easily distracted from their current direction are inherently better
Lie: specialization is safe and necessary in order free common people from making decisions that could be harmful to their well-being; or harmful to the well-being, expansion, or unity of the group

Things that Christians can learn from postmodernism (with some slight differences):

• Truth is generated by individual experience (example: the prophets' experience with God, a person following the Holy Spirit): Though truth is not technically "generated" in the Bible's view, truth is often discovered and recorded by individual experience, and some of it (other than history and prophecy) can only be verified by individual experience.
• There are no moral absolutes: This is Biblical because in the Bible's view, the only reason for any type of "rule" is to show an example of love. In universities, the example is often given that America's involvement in World War II was no less evil than Hitler's, and that perhaps fewer people would've died overall had we let him fail on his own, which he would have (though I disagree with isolationism in that case, the point remains that details matter and simplifying war into good vs evil is not wise). There is no set of morals written in the stars that both God and man must follow to become or remain good. Therefore, the individual's relationship with God and others is the actual standard--there is no need for rules, or to come up with a more detailed list of rules (such as Kosher, prohibiting alcohol, prohibiting sexuality further than it being reserved for one's self or between man & woman married to each other) when people aren't sure whether they are following previous rules (such as Levitical law or even just the ten commandments, or examples of morality/immorality in the New Testament). As a side note, if non-Christians understood this truth of postmodernism better, they couldn't honestly say Yahweh is evil for putting certain people to death regardless of age (it would only be evil if humans made it up, or if Yahweh was not creator and ultimately the person who chooses how every person dies anyway).
• Each person has a map of reality (in the brain)--no one has the universe itself in their head, therefore no one has a perfect map. Instead of knee-jerk reactions such as "The Bible is the map," or "Map theory is dangerous," a better way of dealing with map theory is that: We are always renewing our minds, which will never be perfect until we have a spirit body and the flesh is disposed, but our goal should be to improve, and what we do know is enough to make choices that would allow us to be (accurately) judged or accepted by God, and to know God on a personal level (since he is willing to communicate in a relatable way) though is mind is far beyond ours.
• Individual experience and diversity of viewpoints is more important than precedent--this is why at college you might be taking "insert random civilization here" (such as "Amazon Women of West Africa") instead of World History for your history credit. Unfortunately for Christianity, Church history has often been used as authoritative precedent. Instead, the reason scholarship (basing studies on those who came before) is important primarily so that you can avoid their mistakes. The meaning of history in Christianity is the same as the meaning of history in any other area--to see the outcome of particular views, not as a precedent for how to live or think.
• Communication is inherently flawed, because words are received differently by each person due to their culture and even individual experiences. Instead of Christians denying this fact, they should embrace it and explore (and teach) ways that truth can be determined in spite of it. I often respond to this aspect of postmodernism by saying, that is why the Bible is so long and is written from so many perspectives, by authors in various occupations, cultures, and ages--it has enough information and points of view so that you can understand exactly what the creator intended so that you can know him, and, you can understand what he expects in order to be reconciled with your creator.