Dr. Albert Mohler, a Christian teacher I'm thankful for, writes about evangelism in a post-Christian world.
In our culture, people who think themselves autonomous will claim the right to define all meaning for themselves. Any truth claim they reject or resist is simply ruled out of bounds by society at large. We will make our own world of meaning and dare anyone to violate our autonomy.
This is why evangelism is often perceived as insensitive or even threatening in our culture. Evangelism demands that we press the authority of Scripture and the claims of Christ on sinners as we invite them to the free gift of salvation provided through Christ’s atoning work.
In a post-Christian age, evangelism will be met with one of three responses. First, evangelism will be met with hostility. This will not necessarily take the form of overt action. But, at least in the immediate future, much of this hostility will look like cultural marginalization. Anyone caught inviting sinners to repent of their sin and turn to Christ will be seen as backward or even culturally subversive.
Second, evangelism will also often be met with befuddlement. In a world that has lost fundamental Christian presuppositions about the holiness of God and human accountability, the call of the gospel will more often perplex than infuriate. The plausibility structures of society are so different from our own that many people simply cannot understand us.
Finally, we will find that we will not only be met with hostility and befuddlement, but also indifference. Many in our society will not even care enough about our message to spend their energies either in hostility or befuddlement.