Some of the most controversial conversations among missiologists revolve around the topic of contextualization. This idea touches on a variety of practices. But at its most basic, it refers to a theological and missiological process that presents the gospel in both word and deed, using forms that are appropriate for people of a certain cultural context. When done well, contextualization demonstrates the relevance of the gospel and results in indigenous expressions of the faith.
Poor contextualization results in syncretism—the blending of ideas to the extent that the core meaning is changed beyond recognition.
In the U.S., we see the most prominent form of Christian syncretism in the prosperity gospel movement.