Joshua 1:9
Have I not commanded thee? Be strong and of good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee whithersoever thou goest. (KJV)

There are at least 110 times in the scriptures where it references the words "fear not." However, every time God tells us not to fear, He also tells us the reason why: for the Lord thy God is with you where ever you go.
God told Joshua this very thing when Joshua found himself in a frightening situation. You see, when Moses died, Joshua had to take his position. Do you know what type of leader Moses was?
I mean, those people were use to a man who struck a rock and water came forth, who prayed and manna fell from heaven, who stretched forth his rod and parted the Red Sea. I mean, he had such a strong anointing on him that no one's clothes wore out during those 40 long years in the wilderness.
Now I ask you, how would you like to come behind somebody like that? Yet, God told Joshua, "Only be strong and very courageous." In other words, have a lot of courage and stand before this people and expect them to follow you despite how you feel.

God tells Joshua this again and again. Why? He knows that what we say and do have a lot to do with whether we function in faith or fear. So He commanded him to not to be afraid. And God reminded Joshua that He is with him. Well, Joshua got a hold of that revelation and eventually took the people over into the promised land.

And God is telling you to "fear not" today. God will never leave you. You don't have to fear anything for the Lord is with you where ever you go.
We find elsewhere in scripture, David's assurance of God's presence with him. When he had to face Goliath, the giant, he ran toward him instead of running away from him. He threw a stone with his slingshot and whop! It hit him right between the eyes and knocked him out (see I Samuel 17). I know what happened. An angel got behind that rock and gave it some extra velocity.

Now, why was David not afraid? Because He knew he had a covenant with God; therefore, he was confident that God was always with him.
What giant are you facing today? Well, the very same anointing that was on David is on you, and it will do the same thing with any Goliath in your life.
Scripture References: Joshua 1:1-18; Hebrews 13:5-6