The command in Matthew 28:19 was to reach panta ta ethne and its corresponding promise of success is in Matthew 24:14 —
And the Good News about the Kingdom will be preached throughout the whole world, so that all nations (pasin tois ethnesin) will hear it; and then the end will come.
The scope of the command and the scope of the promise hang on the meaning of panta ta ethne.
- The Old Testament context of Jesus’ missionary commission in Luke 24:46-47 shows that panta ta ethne would most naturally have the meaning of “all the peoples or nations.”
- Mark 11:17 shows that Jesus probably thinks in terms of people groups when He envisions the worldwide purpose of God.
Therefore in all likelihood Jesus did not send His apostles out with a general mission merely to win as many individuals as they could, but rather to reach all the peoples of the world and thus to gather the sons of God which are scattered and to call all the ransomed from every tongue and tribe and people and nation, until redeemed persons from all the peoples praise Him.
Thus when Jesus says in Matthew 24:14 that the gospel must first be preached to panta ta ethne, there is no good reason for construing this to mean anything other than that the gospel must reach all the peoples of the world before the end comes.
He Himself is building His Church from all the peoples. All authority in heaven and on earth have been given to Him for this very thing.