Brigham teaches that there is no singular revelation that "is perfect in its fulness"; God speaks to people according to our abilities.
Brigham Young, "The Kingdom of God," July 8, 1855, Journal of Discourses, 26 vols. (Liverpool: F.D. Richards, 1855), 13:314
I do not believe that there is a single revelation, among the many God has given to the Church; that is perfect in its fulness. The revelations of God contain correct doctrine and principle, as far as they go, but it is impossible for the poor, weak, low, grovelling, sinful inhabitants of the earth to receive a revelation from the Almighty in all its perfections. He has to speak to us in a manner to meet the extent of our capacities.