Paul's words on this subject are the most sublime, the natural man receiveth not the things of the Spirit of God: for they are foolisness unto him: neither can he know them, because they are spiritually discerned (1 Cor 2:14). See also commentary for Mosiah 3:19.
Joseph Smith
"There are but a very few beings in the world who understand rightly the character of God. The great majority of mankind do not comprehend anything, either that which is past, or that which is to come, as it respects their relationship to God. They do not know, neither do they understand the nature of that relationship; and consequently they know but little above the brute beast, or more than to eat, drink and sleep. This is all man knows about God or his existence, unless it is given by the inspiration of the Almighty.
"If a man learns nothing more than to eat, drink and sleep, and does not comprehend any of the designs of God, the beast comprehends the same things. It eats, drinks, sleeps, and knows nothing more about God; yet it knows as much as we, unless we are able to comprehend by the inspiration of Almighty God. If men do not comprehend the character of God, they do not comprehend themselves." (Teachings of the Prophet Joseph Smith, p. 343)