Here the Scripture is speaking of the kind of fear that effectively paralyses a person from taking a course of action that would actually be beneficial to that person. There is another kind of fear that the Bible speak of, but in that context it is in reference to the fear of the Lord, or, a good healthy respect and reverence for the King and Creator that He is. That is not what we are concentrating on here.
Unhealthy fear leads to mistrust, apprehensions, trepidations, suspicions ect... , all of which are not always necesarily of God. There are times when the Holy Spirit will give you a "check" in the spirit about something that you forgot or that is about to happen, something like "feeling" that something just isn't right, but that isn't the same thing as walking around in a spirit of anxiety caused by suspicions and fears related to a threat to your security or well-being. Living in fear can actually make you physically sick, as all that stress puts enormous pressure on your whole system.
The devil loves it when you are in a state of fear, for then you are vulnerable to his lies. Fear gives birth to things such as choler and anger and even rage at times, and these elements attract the devil and his mignons like a magnet. The devil is not omnipresent, like the Lord is, and so he needs something to attract him to you, and unnatural fear is one of those things. And once he has his foot in the door, having gotten your attention by placing you in a state of fear then he can work his dirty deeds. The Bible says that we are not ignorant of his (the devil's) devices (2 Cor 2:11)
A lovely story is told in the Poems section of this site about a donkey that fell in a well, and what ensued demonstrates the difference between reacting in fear and reacting in prayer. The difference can be life and death. Panic and fear would have cost him his life, but taking the moment to slow down and listen to the calming and reassuring voice of the Lord gave him faith and a plan, even in the midst of darkness, that ended up saving him.
What are the telltale signs of the Spirit of God ? The Bible tells us that, " But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, meekness, temperance: against such there is no law ." (Gal 5:22-23) These are the signs of the Spirit of God, not fear . There are all kinds of unnatural fears that torment people, although most of them are based on fear of the furute in some capacity. When you are serving the Lord and doing what He wants you to do, then you don't have to worry about the future, you know it's in good hands, 'cause you are trusting the Lord and you know He will take care of you somehow, sometimes even in the midst of total darkness, He will give you a way out if you will just take it one step at a time, like the donkey in the story.
" Fear not, little flock; for it is your Father's good pleasure to give you the kingdom ." (Lk 12:32) The Lord wants you to have your needs met, He wants you to be happy, and that is why He has set it up so that if you can only trust Him and do the things that He has asked, that He has promised to take care of those needs. " But seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you ." ( Mt 6:33) Read the whole chapter of Matthew 6, it will help you learn to trust the Lord.
So, the next time you see someone and all that they have to say to you is to get you to live in a spirit of fear and anxiety, consider just who it is they are really working for and what is the source of their inspiration, and then read your Bible and " Commit thy works unto the LORD, and thy thoughts shall be established ." (Pro 16:3)