Light is a signal. When you boost a signal, you boost both signal and noise, which are respectively like wheat (what is beneficial) and tares (what is not). Some people never boost their signal at all. They will die with the same paucity of truth they obtained at some early point in their lives. They will most likely have all the noise intact, because it is impossible to ferret out the noise without acquiring new truth in the process.
Some people are good at opening their aperture for truth. They are very open-minded, and consider a broader and deeper range of ideas than most people. Because they take in more truth, they will likewise end up with more noise to filter. The open-minded intentionally suspend judgment until any new information has been considered, but they need not skip judgment.
The odds of a person being open-minded and the probability of that same person having increased discernment seem to be independent. Open-minded people seem to be just as likely to have an aptitude for discernment as closed-minded people. Because of the combination of likelihood of low discernment and an increase in ideas considered, open-minded people tend to be easily derailed in their pursuit of truth by ideas that are absolute nonsense. They tend to be non-conformist and unconventional, but not in necessarily advantageous ways. Without developing discernment—the ability to filter—the open-minded will be disadvantaged compared to the close-minded.
There is a difference between being open-minded and being undiscerning. The scriptures state that “The simple believeth every word: but the prudent man looketh well to his going.” (Proverbs 14:15) Surely, it is wise to be prudent. One must consider “his going,” or question their current understanding of life, salvation, the commandments, their principles, and how they are applying them.
The undiscerning do not differentiate between options—they have no standards and do not sort. Pigs are undiscerning. They will eat anything given to them. When a messenger starts preaching a contrarian message, the majority of people who are attracted to such a message are the undiscerning, because the odds of being both open-minded and discerning are lower than the odds of being open-minded and undiscerning. After a culling period (typically when they are asked to sacrifice something) their numbers thin out. Do not cast your pearls before swine.
Those who acquire the most light are not like pigs, but like whales. Whales spend their days sucking in massive quantities of chaotic waters, filtering out the tiny organisms that provide it with food. They spit out everything else.
Differentiation of the good from the bad requires raw experience. The more you venture into the unknown, the more good you can mine. When we learn what is good and what is bad in this new experience, we transform the unknown into the known. As we discard the bad, we retain elements of the unknown that are good, forging incremental improvement in our character.
Wheat and tares look the same until it is time for harvest (see Matthew 13:24-30). You can’t weed out the tares until it is time for harvest, because only in the appearance of their fruit do they look different. Because truth is progressive, you have to continually retest the truths that you have already acquired. It is unavoidable that your wheat will contain tares, and when your knowledge on a topic is young, it is by design that it be so. As you grow in that topic, the time when it is appropriate to have tares among your wheat comes to an end. As you grow in light, you will find that some of what you previously held to be true requires further distinction. There will be some tares scattered throughout your wheat, and in some cases, some or even all of what you thought was a patch of wheat will be tares. Weeding your field is a process that never ends. You will always have to reevaluate your beliefs—incorporating new observations, asking new questions, and learning new things.
As you acquire more truth, you will need to reinterpret what you previously learned based on your advanced awareness and your advancing understanding of good and evil. In the scriptures, this process is sometimes referred to as “searching in the light of Christ.” The parable of the wheat and tares provides a sense of security in our search for truth, without which it may seem too unsure to venture into. In searching for truth, there is no risk of losing anything of value—all wheat must be preserved in any filtering routine. Any observations or experiences of value within a later-proved belief must be addressed in a replacement belief. You shouldn't fear putative truth. If it turns out false, you can be that much surer of your current views. If it turns out true, you have advanced in your knowledge and will reap the advanced benefits.