Dear noble brothers, there is a close relationship between fear and perception. The child, whose father takes him to the farm, will not be afraid of a snake when it passes by him, but rather he may touch it. Fearing, therefore, is related to perception, and the more man perceives things the greater his fear will become.
Basically man is molded to fear things; otherwise he will not fear Hellfire or Allah's Punishment. Although being fearful is a negative characteristic, it is in the best interest of man, but how? To explain this point, think of an electronic appliance you have at home. It might cost millions, so to save it from any harm, a fuse is installed in it so that if the current is higher than it should be, the fuse will melt down and the power will be off which will save the appliance.
In my view, fear is one of the greatest blessings from Allah the Almighty. Without fear, there will be no obedience to Allah, no Jannah, no Hell-fire, and no steadfastness. The merchant fears cheating, because he knows that Allah the Almighty will cause him bankruptcy, the lawyer fears lying to the client, because he knows that Allah the Almighty will make him face problems, the believer fears disobeying Allah, because he knows that he will lose his ability to approach Him, and so on. This is how we can consider fear a positive characteristic, although it is apparently negative.
I remain steadfast, because I fear Allah the Almighty, I fear that I might lose my relationship with Him, or I fear that my rank in His Sight will be less than it should be. These are some aspects of fearing Allah, and they manifest how fear is a positive characteristic even thought it seems to be a negative one.