So mission will not end when the last of the people groups is reached. We are not sent because of the temporary need in the world (which is indeed great!) because God is a sending God and He is glorified in our obedience. We must recognize that mission is the very nature of God and the basis of our relationship to Him. Mission isn’t a task to be finished, it’s our identity in Christ.
E. Goodman, The Anthropological Approach to Missions
Mission did not begin with the the Great Commission, nor with our modernistic interpretation of people groups in the 1970′s. Mission is the movement of God. It will not end when all the “unreached” have been “reached,” or when the “unengaged” have been “engaged” (and none of those words are biblical). No, mission will end when we are gathered around the throne, worshiping at the foot of the Most High God.