This question is difficult to answer because of the breadth of the phenomena referred to as "postmodernist". Philosophically speaking, post modernism would claim that the task of defining itself is pointless because no one can be confident of the truth of the observation. So, in effect, post modernism reduces what is presented, through deconstruction, to an array of discrete items whose relationships are negotiated by people when they attempt to communicate their experiences of those items. All meaning is negotiated. Truth is negotiated. Objectivity is negotiated. Reality is a pretence because the only existence is the negotiation.
Lyotyard ( ) described post modernism as "that which searches for new presentations ... in order to impart a stronger sense of the unpresentable" (quoted in Strangroom, Jeremy (2006). Philosophy. Sydney: ABC Books, p.127).
This worldview appears to be reflected in the views of young Australians I meet in the classroom when I attempt to teach a subject called Religious Education.
Courage is an ennobling human virtue which can be recognised in people's attempts to live in a post modern world and to carry out the search for faith when all that seems to exist are merely appearances of "the unpresentable", to use Lyotard's description. It is also evident in th empower of human imagination: to construct the possibility of a reality that probably does not exist.
Post modernism is about shifting ground which is probably not shifting and might not / is probably not ground, except for what has been negotiated.
This appears to be the experience of attempting to teach adolescents about God as the object and subject of their search for faith.