I do not think for a moment that the church should aspire to become irrelevant. There is always a need for Christians to speak the gospel into their own context. Rather, my concern is with the ever present danger of over-contextualizing. Consider what happens to a church that is always trying to appeal to an increasingly post-Christian culture. Almost inevitably, the church itself becomes post- Christian. This is what happened to the liberal church during the twentieth century, and it is what is happening to the evangelical church right now. As James Montgomery Boice has argued, evangelicals are accepting the world’s wisdom, embracing the world’s theology, adopting the world’s agenda, and employing the world’s methods. In theology a revision of evangelical doctrine is now underway that seeks to bring Christianity more in line with postmodern thought. The obvious difficulty is that in a post-Christian culture, a church that tries too hard to be relevant may in the process lose its very identity as the church. Rather than confronting the world the church gets co-opted by. It no longer stands a city on a hill, but sinks to the level of the surrounding culture."
Philip Graham Ryken, City on a Hill: Reclaiming the Biblical Pattern for the Church in the 21st Century (Moody Press, 2003), 22.