In all evangelism there is… a cultural gulf to bridge. This is obvious when Christian people move as messengers of the gospel from one country or continent to another. But even if we remain in our own country, Christians and non-Christians are often widely separated from one another by social sub-cultures and lifestyles as well as by different values, beliefs, and moral standards. Only an incarnation can span these divides, for an incarnation means entering other people’s worlds, their thought-world, and the worlds of their alienation, loneliness, and pain. Moreover, the incarnation led to the cross. Jesus first took our flesh, then he bore our sin. This was a depth of penetration into our world in order to reach us, in comparison with which our little attempts to reach people seem amateur and shallow. The cross calls us to a much more radical and costly kind of evangelism than most churches have begun to consider, let alone experience.
From John Stott's "The Cross of Christ":