You see, most of the unreached tribes NTM works with have an animistic worldview which means they think very differently than the average Westerner.
Animists believe that spiritual beings and forces have power over the daily lives of humans. So they invest much of their time and energy into figuring out which beings or forces impact them. Then they strive to keep those forces happy, or even manipulate them to their advantage. Believing that spirits control health, crops, hunting, etc. might sound a little crazy, but the animistic worldview is as logical as our secular American worldview if you simply accept the basic assumption that spirits and forces shape reality.
You see, to arrive and immediately start teaching about Jesus is to assume they already understand key foundational truths such as sin, death, and an all-powerful God. Instead of uprooting the old worldview and building a biblical one, the missionary would be tacking on a Christian vocabulary to an animistic worldview. They would be adding ‘Jesus’ to a list of other spirits in the tribe. As one missionary put it, “We don’t know what we don’t know and assume everyone thinks like we do. We think we are communicating one thing and all the while we are communicating something different.” The result is people who believe they are right with God but are far from it. This is very dangerous – possibly the worst place a person can be!