“[God] is using not only his covenant people, but other peoples as well, to consummate a work, stupendous, magnificent, and altogether too arduous for this little handful of Saints to accomplish by and of themselves. …All down the ages men bearing the authority of the Holy Priesthood—patriarchs, prophets, apostles and others, have officiated in the name of the Lord, doing the things that he required of them; and outside the pale of their activities other good and great men, not bearing the Priesthood, but possessing profundity of thought, great wisdom, and a desire to uplift their fellows, have been sent by the Almighty into many nations, to give them, not the fulness of the Gospel, but that portion of truth that they were able to receive and wisely use.”

Elder Orson F. Whitney, (In Conference Report, Apr. 1921, pp. 32–33.)

Quoted by Howard W. Hunter: http://www.lds.org/general-conference/print/1991/10/the-gospel-a-global-faith?lang=eng