I think that I am at an advantage in ministering to a post-Christian society in that I became a Christian as an adult, and so I can readily think like a secular person. It's fairly easy for me to spot Christian presuppositions in evangelical efforts that are not self-evident to the secular person. Victor Reppert writes:
I have taught in both a Christian setting and a non-Christian setting, but most of my student career and my teaching career has been in secular institutions. I often find that in a non-Christian setting students seem unaware of the fact that they have a world-view, or else they haven’t really thought very clearly about what their world-view is and how to make it a consistent one. So you find people drawing from one source here and one source there whenever it suits them. In a Christian setting you will still find some of that as well. But the main issue that I believe I should try to come to terms with in dealing with Christian students is the fact that they have learned certain ways of talking about what they believe which are common in churches but have little meaning to anyone outside of four walls of the institutional church. One church outsider came to a church and was asked “Are you under the blood?” which prompted him to look up at the ceiling to see if there was some red liquid coming down. Consider even a phrase like “Christ paid the penalty for our sins.” What penalty? What sins? And how could Christ pay it, if we incurred the penalty?
Missionaries often spend years studying the peoples of the countries in which they minister, hoping to understand the thought-forms of those peoples, so that they can learn to present the Christian message in a way that is meaningful to the people of that culture. Yet, I think, a lot of Christians have no idea how their world-view differs from the world-views of others, or how to ask the questions a non-believer would ask.
If Christians want to be effective evangelists -- or even effective thinkers -- they must engage in depth points of view other than their own.