A community of people who adopt Christianity as an alternative basis for living, beyond a set of propositional beliefs, becomes a powerful apologetic in the postmodern culture. Truth is found when individuals live in an authentic life-changing community because, what brings together absolute truth and relative truth is relational truth. God sent us a person, Jesus, not a proposition.
Stanley Grenz, in an interview in Cutting Edge Magazine explains this hermeneutic as:
In the postmodern context, we are moving toward the community evaluating a mosaic's pragmatic usability. The community has tremendous power in the postmodern context. Individualism is a modernist concept. The individual in the postmodern context becomes a person-in-relationship. So it's not like I can stand as an individual observer looking at alternate communities and subjectively determining which is right or which mosaic happens to be intellectually best. Rather, it is only as I participate in community, involved in the give-and-take of that community life, that I see what its mosaic is all about.
In other words, to know Jesus, to know what christianity is really truely about, is only possible by active participation in the life of a community of believers, and not by learning propostional truths/facts about Christianity (even if we affirm there are propostional truths about Christianity). And in terms of others finding out about christianity, our best apologetic (and often our worst!), is the community that live around their faith.