More than 70% of Christian effort and ministry is directed at people who already profess to be Christians, while less than 5% of our total missionary activity is focused on those who have never once had a chance to hear about the good news of the Gospel. (Source: Center for the Study of Global Christianity).
CSGC is the best source on getting accurate data on global Christianity.
“At present, some 95% of all Christian debate and discussion on these matters deals only with mission in the midst of the present Christian world. Another 4% concerns mission in the evangelized non-Christian world. Less than 1% of all thinking, discussion and action concerns mission among the unevangelized. The church’s viewpoint is almost incurably self-centered. In our opinion, the greatest enemy of world evangelization is Christian rhetoric–the continual rhetorizing, playing the orator, discussing, arguing, the endless talking and preaching about evangelizing the world without any of the crucial implementation. The rest of the world would be relieved and grateful if all Christians would once and for all replace good intentions, rhetoric and broken promises with solid achievements.”