Postmodern theology, or in fact anything to which the term ‘postmodern’ is affixed, does not define a school of beliefs or a set of defined precepts recognizable as truisms. Postmodernism is an approach or a practice that seeks to be critical and employ comparisons and differences to deconstruct or destabilize certainty. This view or approach makes the theology of numerous religious perspectives a prime target.
Postmoderism primarily rejects the idea of objectivity, there are no descriptions of definitions that are neutral. In this sense, any postmodern field of study is basically saying that field is without objectivity, without certainty, everything is open to interpretation. 
- Vanhoozer, J. K. (Ed) (2003) “Theology and the conditions of postmodernity - A report on knowledge (of God)” in The Cambridge companion to postmodern theology'. Cambridge University Press; Aylesworth, Gary, "Postmodernism", The Stanford Encyclopedia of Philosophy (Winter 2010 Edition), Edward N. Zalta (ed.),