It is remarkable that God has committed to us preachers the ministry of the Word for the ruling of men’s hearts

Martin Luther on the Preaching of the Word.

It is remarkable that God has committed to us preachers the ministry of the Word for the ruling of men’s hearts, which we can’t look into. But this is the office of God, who says to us, ‘Preach! I shall give the increase. I know the hearts of men.’ This should be our comfort, even when the world laughs at our office. – 1536