"I have learned by experience that there is but one God that pertains to this people, and He is the God that pertains to this earth--the first man. That first man sent his own Son to redeem the world, to redeem his brethren; his life was taken, his blood shed, that our sins might be remitted. That Son called twelve men and ordained them to be Apostles, and when he departed the keys of the kingdom were deposited with three of 
those twelve, viz.: Peter, James, and John"  (Journal of Discourses 4:1).

http://jod.mrm.org/4/1