Luke 12:4-7 (ESV)
"I tell you, my friends, do not fear those who kill the body, and after that have nothing more that they can do.  But I will warn you whom to fear: fear him who, after he has killed, has authority to cast into hell. Yes, I tell you, fear him!  Are not five sparrows sold for two pennies? And not one of them is forgotten before God.  Why, even the hairs of your head are all numbered. Fear not; you are of more value than many sparrows.
I’m told these days, often enough, that fearing God doesn’t mean the same thing as fear in other cases. That God does not want us to fear him, but respect him or some such nonsense. Listen, you have to be an idiot not to fear God. And by fear God, I mean fear him. Jesus minces no words. Don’t fear the guy who can kill you, fear the guy who can throw you into hell when he is done killing you. That person is God. Not the devil. We don’t need to fear the devil, he isn’t even in the same league as God. When it comes to the devil, take Luther’s advice and fart in his face, taunt him. But fear God.
Thing is if you fear God, you have nothing else to fear. Those who don’t fear God, they are the ones who fear the devil, fear the government, fear other men, fear war etc. Those who don’t fear God, live a life of fear. Fear God, and live a life of grace and freedom, even freedom from fear. Why? Because fear of God is but the beginning of wisdom, full wisdom teaches you to trust and love also. Fearing God is the beginning of faith, which learns to trust and love God above all things, even as it fears God above all things. Faith, knows that God can do all these things, he can kill you, and throw you into hell, but too God you are worth far more than many sparrows, and God cares for them. None are forgotten before him.
So in fearing God, we learn to let go of fear for other things, fear of familial rejection, fear of so called friends who would laugh at you for going to church, or not engaging in sexual immorality, fear of society who would dictate norms of right and wrong at variance with God’s word. Yes, when we don’t fear God, the rustling of a leaf is cause for fear. Fear God, and there is nothing left to fear. For he has purchased you not with pennies, but with blood, with love, the sacrifice of his own son for your sins, for your fears.