The most difficult subjects can be explained to the most slow-witted man if he has not formed any idea of them already; but the simplest thing cannot be made clear to the most intelligent man if he is firmly persuaded that he already knows, without a shadow of a doubt, what is laid before him.Leo Tolstoy, The Kingdom of God Is Within You
There is a school of thought out there that I have come across that frowns upon certainty or is at least highly skeptical of it. Tolstoy’s quote points out how hard it can be to change one’s mind if they are “firmly persuaded” that they “already know”.
“O that cunning plan of the evil one! O the vainness, and the frailties, and the foolishness of men! When they are learned they think they are wise, and they hearken not unto the counsel of God, for they set it aside, supposing they know of themselves, wherefore, their wisdom is foolishness and it profiteth them not. And they shall perish. But to be learned is good if they hearken unto the counsels of God.”2 Nephi 9:28-29
“Wo be unto him that shall say: We have received the word of God, and we need no more of the word of God, for we have enough! For behold, thus saith the Lord God: I will give unto the children of men line upon line, precept upon precept, here a little and there a little; and blessed are those who hearken unto my precepts, and lend an ear unto my counsel, for they shall learn wisdom; for unto him that receiveth I will give more; and from them that shall say, We have enough, from them shall be taken away even that which they have.”)2 Nephi 28:29-30
The scriptures from the Book of Mormon likewise talk about “know[ing] of themselves” and thinking that you “have enough” knowledge.
The Lectures on Faith stress the necessity of obtaining an “actual knowledge.”
“An actual knowledge to any person that the course of life which he pursues is according to the will of God, is essentially necessary to enable him to have that confidence in God, without which no person can obtain eternal life. […] Such was and always will be the situation of the saints of God, that unless they have an actual knowledge that the course that they are pursuing is according to the will of God, they will grow weary in their minds and faint;” (Lecture 6:2,4)
Actual knowledge is more than firm persuasion or knowing of yourself or feeling as though you have enough. In my experience, actual knowledge involves a literal experience with the divine that communicates intelligence that is clearly understood.
Such clarity is empowering and makes people more like God in that they are more faithful, kind, benevolent, charitable, and full of love toward their fellow man. More long-suffering, tender, merciful, and willing to endure suffering with patience and a peaceful temperament.
Actual knowledge from God tends to transform people rather than just inform them.