In 1974 Christians were rejoicing that there were now believers in every country in the world. If the Great Commission was conceived as a geographic command to preach, then it had been fulfilled. It was at Lausanne in 1974 that Ralph Winter was the first to argue that the Bible did not primarily see the world in geopolitical terms, but instead conceived of the world as populated by ethnic blocks.
Today there are three organizations the produce data to help Christians understand the current status of global evangelism. They each define a people group differently. This is why you might see different organizations list different numbers of unreached people groups. Here are the three:
Defintion: the largest group within which the Gospel can spread as a church planting movement without encountering barriers of understanding or acceptance.
Number of People Groups in the World: 16,304
Number of Unreached People Groups: 6,748
World Christian Database
Defintion: Primarily defined along ethno-linguistic, meaning that a people group is usually defined by language. Within a language group other factors such as race, tradition, history, and culture sometimes define a subsection of peoples.
Number of People Groups in the World: 13,611 people groups/621 megapeoples
Number of Unreached People Groups: 112 megapeople groups with no access to the gospel
International Missions Board
Defintion: an ethnolinguistic group with a common self-identity that is shared by the various members.
Number of People Groups in the World: 11,571
Number of Unreached People Groups: 6,450
Darren Carlson is the Founder and President of Training Leaders International. As President, Darren oversees the general direction of the ministry and serves as an advocate for pastors with little access to formal training and thoughtful cross-cultural theological engagement. You can connect with him on Facebook and Twitter.