And he said unto them, Go ye into all the world,
 and preach the gospel to every creature.
Mormon 4:86


And again, this gospel of the kingdom
shall be preached in all the world,
 for a witness unto all nations
Matt 24;32




Now, behold, a marvelous work is about to come forth among the children of men, therefore, O ye that embark in the service of God, see that ye serve him with all your heart, might, mind, and strength, that ye may stand blameless before God at the last day; therefore, if ye have desires to serve God, ye are called to the work, for, behold, the field is white already to harvest, and lo, he that thrusteth in his sickle with his might, the same layeth up in store that he perish not, but bringeth salvation to his soul; and faith, hope, charity, and love, with an eye single to the glory of God, qualifies him for the work.
Doctrine & Covenants 4:1