The protection from all evil is dependant on fear of Heaven. Now, it is known that there are two types of Fear. One is called “external fear,” which is when one fears the punishments in this World and the Next. But this type of fear is an “inferior fear,” as the Zohar calls it, because it means that the person is not truly in awe of Hashem but is actually afraid for his own self. Nevertheless, even this type of fear is good because through the imperfect motive the person will come to the ideal motive. Pure “fear of Heaven,” however, is one the person is in awe of the greatness of Hashem, for He is Great, and there is no limit to His greatness, to the perfection of His Attributes, and to His knowledge. Not every person merits having this type of fear. It all depends on the person’s arousal and deeds and on the consistency with which he studies works that teach man knowledge and Fear of Heaven.
Among the most important traits needed for anything holy are effort and diligence. We know that it is a mitzvah to fear the Awesome and Great God, that in fact it is one of the 613 mitzvos, that it is fundamental, that it is a constant mitzvah, and that every moment one remembers to fear Hashem he fulfills a Scriptural mitzvah. It is one of the things that a person can never say that he could not keep it, for it is a mitzvah one can fulfill at all times—while sitting at home, walking on the road or while with a group of people. In all these situations or when involved in one’s affairs or sitting in the store, he should not let his heart be idle; rather, he should think pure thoughts and by doing so he will be fulfilling mitzvos.
It is very beneficial to recite the verse, I have set Hashem before me always (Tehillim 16:8). Now, this mitzvah of Fear of Hashem leads to additional things that protect us from all evil. Fortunate is the person who is constantly afraid that perhaps he caused displeasure and anger to the great, exalted and awesome King. The person will then shudder at the thought of any evil and he will do good in order to bring pleasure to his Maker.