The term postmodernism means many different things. However, postmodernist philosophy, generally understood, claims to leave behind modernist (or Enlightenment) commitments to the objectivity of truth, the universality of reason, and the inevitability of progress. Instead of attempting to fashion a rational worldview, postmodernism opts for lesser goals by cobbling together various ideas, practices, and goals for pragmatic purposes. As postmodernist Walter Truett Anderson puts it, "Truth isn't what it used to be." Postmodernism embraces a cluster of ideas, most of which contradict the Christian understanding of truth, authority, and rationality. (One positive note is that postmodernism tends to deflate overly optimistic accounts of human reason and progress based solely on human ability.)
Postmodernists claim that any comprehensive and authoritative worldview is forever out of reach and that to claim otherwise is an arrogant pretext for dominating , those with whom one disagrees. For example, claims for the objective truth of the Christian worldview are unwarranted and lead to the oppression of non-Christians: Such "metanarratives" (Jean-Francois Lyotard), or stories used to describe reality as a whole, must be abandoned. No worldview holds any objective or rational authority over any other.
Thinkers such as Jacques Derrida "deconstruct" texts in order to abolish their authority. Texts do not possess any knowable or rational meaning established by the author and discernible by the informed reader. Their meaning is variable and open ended. The text has no authority. The reader contributes decisively to the meanings (plural) of texts. Thus deconstruction undermines the truthfulness of any text (including the Bible) since no text contains a single meaning that may correspond with objective facts. (Ironically, deconstructionists decry "misinterpretations" of their own writings.)
For postmodernists, "truth" is fundamentally a social, linguistic construction devised for a certain purpose. Various cultures have their own "maps," which describe reality differently. However, we cannot determine which "map" connects more closely with reality, since we cannot press beyond our own cultural conditioning. . There is no objective reality apart from our languages and concepts. Various communities determine their own truths. There is no God's-eye view of anything and thus no objective truth. As Friedrich Nietzsche declared, "There is no truth, only interpretation."
Against these claims, Scripture claims to be an objectively true revelation from God, authoritative on whatever it speaks (Rm 3:4; 2 Tm 3:15-17). Only God knows reality comprehensively, but humans may attain to partial knowledge by attending to God's revelation and by using their minds in wise ways. The Bible-and most philosophers-claim that a true statement is one that corresponds with reality. Social customs or personal opinions do not create truth; hence the Bible's condemnation of idols as false gods. The statement "Jesus is Lord" does not merely express the cultural language and tradition of Christians. It is a truth claim about objective realities. Moreover, good apologetic arguments may rationally verify the objective truth of this statement.
Postmodernist claims are logically flawed. First, their pronouncements on truth contradict themselves. Their statements claim to be applicable to reality itself, not merely to one's culture. Yet this is just what postmodernists claim cannot be done. In rejecting all objective authority, they end up asserting their own authority and their own metanarrative. This is contradictory and false. Second, sane people judge certain acts-such as the terrorist attacks on America on September 11, 2001-as objectively evil and not as merely relative social constructions. If this is so, the post-modern view of constructed morality cannot be defended. Postmodernism emphasizes the diversity of truth claims, particularly in pluralistic settings, but it provides - no method to test these claims against reality. Instead, it succumbs to a kind of intellectual indifference-the enemy of moral progress and spiritual virtue.
Although no major religion adheres to the postmodern view of truth, this mind¬set has affected how many people view spirituality, particularly in nations with significant religious freedom. Many think that religion is a matter of choice, taste, and preference. One seeks a designer religion that suits one's taste, or one is born into a religion that defines who one is. One may even mix and match elements from several religions. Debating whether a religion is true or false is pointless. All are "true' in the postmodern sense because they give meaning to people's lives. This perspective contradicts the Christian's apologetic duty to address the falsity and rational inadequacy of alternative religions in order to present Christianity as true, rational, and pertinent (2 Co 10:3-5).
Extracted from the Apologetics Study Bible.