Belief is a property that has to do with the perspective and choice of the holder, not the actual underlying truth of the belief itself with respect to reality. This is a strange idea, and yet it is critical to understand if one hopes to achieve more than mediocre outcomes in life and eternity. You can believe and yet not desire, and you can have reasons for a belief and yet choose not to believe it.
Belief exists across layers of confidence. The ability to have high confidence in a belief is based on your perception of the reasons that support the belief, not the set of all reasons (which may, in fact, contradict the belief) that transcend your perception. Your perception of reality is always severely limited compared to all that really is. Even when you are as certain as someone can be about something, your belief could be (and is, in fact, likely to be) incomplete or incorrect.
And yet, incomplete or incorrect beliefs can be highly effectual. All of science and religion alike attest to that fact.
To have unshakable belief in something, you must have reasons. However, those reasons will never be sufficient to finally prove your belief. Only experiencing the outcome can do that.
The uncertainty of belief is extremely important for several reasons.
First, you have to learn to act with the degree of confidence justified by your reasons. You must learn to shift your threshold of action from some concept of fundamental and unchangeable truth to what is sufficiently supported to justify specific actions.
Faith doesn’t operate on a yes or no basis of truth. Faith operates with sufficiently strong reasons to undertake the actions that seem to lead to the outcome at hand, as best you know, for now. That threshold of sufficient confidence for action will be different for every outcome: You don’t need massive reasons for taking a tiny action, and weak reasons are insufficient for massive actions. If you are locked into a cruder gradation of truth, reasons, and actions, you will be as limited in the number and goodness of outcomes you can attain as a child is in what he can build with big wooden blocks versus a full set of Legos.
Second, uncertainty affords you the opportunity to do more than simply walk across some minimum threshold of action. Uncertainty allows you to leap when the reasons support it. This is one meaning of what Jesus meant when he referred to the faith of a child.
We tend to excuse ourselves from belief in big things because we become aware that, while the reasons we know of are clearly in one direction, we simply don’t know everything. Is this not as true in any situation? If you applied that same standard to every situation, you would never act in anything. The question isn’t whether you know everything. The question is: based on what you can learn for now, does reason suggest that a specific set of drastic actions will lead to an outcome that you desire? If so, execute.
The ability to take bold, believing actions in spite of uncertainty is critical to obtaining the best outcomes in life. While God promises to make what is good and what is evil as plain to us as the difference between day and night (see Moroni 7:15), he does not promise that the gravity of the decision will be revealed to us at the outset. In other words, while he will show us which fork in the road is better, he will not typically show us by how much:
Now ye may suppose that this is foolishness in me; but behold I say unto you, that by small and simple things are great things brought to pass; and small means in many instances doth confound the wise. (Alma 37:6)
Those who will act in the most reasonable way will learn, over time, that what they thought were small decisions have made massive differences in their lives.
Third, uncertainty keeps you extremely open to the fact that your belief is incorrect or incomplete. Nascent beliefs, when honestly considered, will either grow until they are sufficient to suggest action, or fade under inspection:
28 Now, we will compare the word unto a seed. Now, if ye give place, that a seed may be planted in your heart, behold, if it be a true seed, or a good seed, if ye do not cast it out by your unbelief, that ye will resist the Spirit of the Lord, behold, it will begin to swell within your breasts; and when you feel these swelling motions, ye will begin to say within yourselves—It must needs be that this is a good seed, or that the word is good, for it beginneth to enlarge my soul; yea, it beginneth to enlighten my understanding, yea, it beginneth to be delicious to me.
29 Now behold, would not this increase your faith? I say unto you, Yea; nevertheless it hath not grown up to a perfect knowledge. 30 But behold, as the seed swelleth, and sprouteth, and beginneth to grow, then you must needs say that the seed is good; for behold it swelleth, and sprouteth, and beginneth to grow. And now, behold, will not this strengthen your faith? Yea, it will strengthen your faith: for ye will say I know that this is a good seed; for behold it sprouteth and beginneth to grow.
31 And now, behold, are ye sure that this is a good seed? I say unto you, Yea; for every seed bringeth forth unto its own likeness. 32 Therefore, if a seed groweth it is good, but if it groweth not, behold it is not good, therefore it is cast away.
33 And now, behold, because ye have tried the experiment, and planted the seed, and it swelleth and sprouteth, and beginneth to grow, ye must needs know that the seed is good. (Alma 32)
As you execute the faith cycle, you will learn more and have many opportunities to revise your belief by changing your desires, reasons, actions, and outcomes. It is all too easy to prefer flawed but comfortable beliefs to uncertain but potentially better ideas. Life is full of scenarios where promising but unknown paths must be preferred to lesser but wellknown paths. Lean on reasoning. Always reconcile yourself to the full implications of what you presently know.
Fourth, there are mechanisms in this universe that operate based on the belief of the actor, independent of the absolute truthfulness of the belief. This property is much more common than you think. Rather than thinking of it as an exception, come to recognize it as the rule. The requirement of so many miracles, for example, is that you believe. While belief is not merely guessing or desiring, it doesn’t require knowing God’s will exactly. Belief means that you have sufficient reasons to believe that what you are asking will actually happen. On the one hand, you need a reason to believe. You will never be able to exercise perfect belief in something you have no reason to believe, or something you have good reason not to believe. Ignorance cannot generate perfect belief. On the other hand, if you have sufficient reason to believe, and insufficient reason not to believe, you must honestly have high confidence in your belief, until given a reason not to.
The ability to steadfastly believe in what you have reasons to believe is not something that is specific to any given belief. It is an extremely accurate indication of one’s honesty, in the most profound sense. One who is integrally honest will be perfectly reconciled to all their beliefs in all things at all times. One who falls short of this standard can’t exercise full faith, because they will always lack the belief necessary to act towards the same outcomes in the same ways as someone who is:
15 Do ye exercise faith in the redemption of him who created you? Do you look forward with an eye of faith, and view this mortal body raised in immortality, and this corruption raised in incorruption, to stand before God to be judged according to the deeds which have been done in the mortal body?
16 I say unto you, can you imagine to yourselves that ye hear the voice of the Lord, saying unto you, in that day: Come unto me ye blessed, for behold, your works have been the works of righteousness upon the face of the earth?
17 Or do ye imagine to yourselves that ye can lie unto the Lord in that day, and say—Lord, our works have been righteous works upon the face of the earth—and that he will save you?
18 Or otherwise, can ye imagine yourselves brought before the tribunal of God with your souls filled with guilt and remorse, having a remembrance of all your guilt, yea, a perfect remembrance of all your wickedness, yea, a remembrance that ye have set at defiance the commandments of God?
19 I say unto you, can ye look up to God at that day with a pure heart and clean hands? I say unto you, can you look up, having the image of God engraven upon your countenances?
20 I say unto you, can ye think of being saved when you have yielded yourselves to become subjects to the devil?
21 I say unto you, ye will know at that day that ye cannot be saved; for there can no man be saved except his garments are washed white; yea, his garments must be purified until they are cleansed from all stain, through the blood of him of whom it has been spoken by our fathers, who should come to redeem his people from their sins.
22 And now I ask of you, my brethren, how will any of you feel, if ye shall stand before the bar of God, having your garments stained with blood and all manner of filthiness? Behold, what will these things testify against you? (Alma 5)
Belief requires shutting down doubt. Doubt is an obstacle to belief, but it is not insurmountable and it is not a bad thing.
Doubt and belief can’t coexist, but the way to vanquish doubt is not through willful insistence (also known as wishing). Instead, it is through learning : through greater observation and reasoning.
When the Lord said, “If ye have faith, and doubt not, ye shall not only do this which is done to the fig tree, but also if ye shall say unto this mountain, Be thou removed, and be thou cast into the sea; it shall be done.” (Matthew 21:21), he wasn’t saying “if you wish really hard, you can move mountains.” He was saying that the presence of doubt belies a lack of understanding how it is that mountains are moved and why trees are withered when cursed, according to God’s knowledge and purposes.
As long as it is honest doubt and not unbelief, doubt is a helpful indicator that suggests you need to spend more effort reasoning about that particular belief. If you find sufficient reason to overcome the doubt, you will have more confidence than previously. If you fail to find sufficient reason in spite of appropriate effort, you have gained freedom from a poorly supported belief, at least until sufficient new information is available.