“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. I want to go back to the beginning, and so lift your minds into more lofty spheres and a more exalted understanding than what the human mind generally aspires to.
“… The scriptures inform us that ‘This is life eternal that they might know thee, the only true God, and Jesus Christ whom thou hast sent.’ [John 17:3.]
“If any man does not know God, and inquires what kind of a being He is,—if he will search diligently his own heart—if the declaration of Jesus and the apostles be true, he will realize that he has not eternal life; for there can be eternal life on no other principle."

Teachings of Presidents of the Church: Joseph Smith