Just like all the other kind of impurities or thought activities in the modification of the mind, fear, worry, and the sense of insecurity are selfless and impermanent.
All kinds of impurities or thought activities are not 'I', and they are impermanent.
All kinds of impurities or thought activities are just what they are. They are neither good nor bad, neither positive nor negative, and neither right nor wrong, especially if there is certain degrees of self-awareness, correct understanding, non-attachment, non-identification, non-craving, non-aversion, non-comparison, non-judgment, and non-expectation in the thinking mind, where the mind is aware of all these impurities or thought activities (regardless of whether they are pleasant or unpleasant/desirable or undesirable) arising, changing, and passing away in the selfless impermanent modification of the mind, without attachment, identification, craving, aversion, comparison, judgment, or expectation towards all kinds of impurities or thought activities that are selfless and impermanent.
Such minds have self-control of not being over-powered by any kinds of impurities/feelings/emotions/ideas (thought activities) that ceaselessly coming and going in the mind, and not generating any actions/reactions/speech/expression under the influence of impurities or thought activities in the modification of the mind that are selfless and impermanent, that would hurt oneself and/or others and the surrounding environment.
It is only when the mind is functioning under the veil of ignorance and egoism, where the mind doesn't know what is non-attachment, non-identification, non-craving, non-aversion, non-comparison, non-judgment, and non-expectation, and hence, the mind is being determined and over-powered by all kinds of impurities or thought activities, and would generate actions/reactions/speech/expression under the influence of impurities or thought activities in the modification of the mind, that might hurt oneself and/or others and the surrounding environment.
Like all kinds of impurities/feelings/emotions/ideas (thought activities) in the mind, the presence of fear, worry, and the sense of insecurity in the modification of the mind is something normal and common in most minds. However, if without correct understanding, self-awareness, and self-control, the mind will be over-whelmed and over-powered by the presence of fear, worry, and the sense of insecurity, that gives rise to all kinds of unnecessary unrest, violence, and cruelty in the world of diversity that doesn't belong to anyone, that is related to selfishness, pride, possessiveness, hoarding, greed, separateness, discrimination, anger, hatred, offensiveness, defensiveness, and so on.
Many minds would think and believe that by acquiring and possessing success and wealth will chase away fear, worry, and the sense of insecurity, but it doesn't.
If without correct understanding, even the wealthiest and most successful or powerful people in the world are also being over-powered by fear, worry, and the sense of insecurity, being the slaves of all kinds of impurities. Those that are free from fear, worry, and the sense of insecurity, they are devoid of discontentment and greed, and they wouldn't be hoarding wealth that gives them the status of wealthiness, that they don't need at all, even if they are highly successful and capable of generating abundant wealth, but they would be using their generated wealth to benefit all the others. However, most minds in the world are not in having such understanding. That's why the world is being what it is, full of all kinds of unnecessary selfishness, discrimination, hatred, unrest, corruption, violence, and cruelty.
The minds that are functioning under the influence of ignorance and egoism, that are being over-powered by all kinds of impurities or thought activities in the modification of the mind, would attack and hurt some others out of selfishness, pride, possessiveness, hoarding, greed, separateness, discrimination, anger, hatred, offensiveness, defensiveness, and so on, under the presence and influence of fear, worry, and the sense of insecurity, even when others have no intention to hurt anyone or anything.
The minds that have correct understanding towards the selfless impermanent modification of the mind, they understand that fear, worry, and the sense of insecurity towards certain outcome or reality that might be unpleasant or undesirable don't and won't change the outcome or reality being what it is, but they are the unnecessary hindrance that would affect/impact/disturb/limit/oppress/reduce the performance of the body and mind while performing certain actions or activities, which definitely will hinder the body and mind to perform at its highest and possible ability, that would affect and determine the outcome/the result/the fruit of action/the reality.
Since fear, worry, and the sense of insecurity doesn't change the outcome/reality to be something else that it is not, or it doesn't help to make the outcome/reality to become better than what it is, but it would definitely affect/impact/limit the action in the present moment to be less efficient/productive than what it could be, that influences and determines the outcome/reality to be less efficient/desirable than what it could be, and hence, why still entertain and empower the presence of fear, worry, and the sense of insecurity, allowing fear, worry, and the sense of insecurity to affect and over-power oneself and one's performance? Under such understanding, the presence of fear, worry, and the sense of insecurity will become less and less, and eventually, it will vanish from the modification of the mind.
All types of yoga practice require attentiveness. Being attentive and careful while performing any actions, duties, and responsibilities will minimize or avoid many unnecessary energy wasting, mistakes, damages, or injuries. Fear, worry, and the sense of insecurity doesn't and cannot exist upon the mind is being fully attentive/focused/concentrated towards what is in now, in the present moment.
Fear and worry doesn't exist in the mind that knows and respects the truth of selflessness and impermanence, where there is no past or future, there is only now. One can do one's best in whatever one is doing, while allowing the fruit of action being what it is. There is no attachment or identification towards the action and the fruit of action. That is freedom.
Inquire the truth of everything, and be free.