From the Word
And he said to them, “Go into all the world and preach the gospel to the whole creation.
Mark 16:15, RSV
He that would preach the gospel must cast aside all works supposed to make one just, and allow nothing to remain but faith; I must believe that God, without any merit of mine and regardless of all works, has granted me his grace and eternal life. Therefore we must preach in a way that the glory and praise will be given to God and not to ourselves. Now there is no greater glory and praise that we can give to God than to confess that out of pure grace and mercy he takes away from us sin, death and hell, and that he gives his beloved Son and all his treasures to us.
Faith compels no one to accept the gospel, but leaves its acceptance free to every one and makes it a personal matter. Thus you see that the pope errs and does the people injustice when he ventures to drive them to faith by force. The Lord commanded the disciples to do nothing more than preach the gospel. This the disciples also did; they preached the gospel and left its acceptance to those who would take it. They did not say: Believe, or I will put you to death.
A question arises as to the words, “Go ye into all the world,” how it is to be understood, since the apostles certainly did not visit all the world? Their preaching went out into all the world, although it has not yet come into all the world. This going out has been begun and continues, although it is not yet completed; the gospel will be preached farther and wider until the judgment day. When this preaching shall have reached all parts of the world, and shall have been everywhere heard, then will the message be complete and its mission accomplished; then will the last day also be at hand.
The preaching of this message may be likened to a stone thrown into the water, producing ripples which circle outward from it, the waves rolling on and on, one driving the other, till they come to shore. The preaching was begun by the apostles, and it constantly goes forward, is pushed on farther and farther by the preachers, driven hither and thither into the world, always being made known by those who never heard it before, although it be arrested in the midst of its course and is condemned as heresy.
Luther, Martin, and John Sander. Devotional Readings from Luther’s Works for Every Day of the Year. Augustana Book Concern, 1915, pp. 172–73.