Doctrine & Covenants 65:2-3

The keys of the kingdom of God are committed unto man on the earth, and from thence shall the gospel roll forth unto the ends of the earth, as the stone which is cut out of the mountain without hands shall roll forth, until it has filled the whole earth. Yea, a voice crying---Prepare ye the way of the Lord, prepare ye the supper of the Lamb, make ready for the Bridegroom.