Joseph Smith taught,

“God is the only supreme governor and independent being in whom all fulness and perfection dwell; who is omnipotent, omnipresent, and omniscient; without beginning of days or end of life; and that in him every good gift and every good principle dwell.” *

“Without the knowledge of all things God would not be able to save any portion of his creatures; for it is by reason of the knowledge which he has of all things, from the beginning to the end, that enables him to give that understanding to his creatures by which they are made partakers of eternal life; and if it were not for the idea existing in the minds of men that God had all knowledge it would be impossible for them to exercise faith in him.” **

*Lectures on Faith, lec. 5, paragraph 2

**Lectures on Faith, lec. 2, paragraph 2

Quoted by Joseph Fielding Smith, Doctrines of Salvation Vol. I, p. 6