With enough "don't be scared" references in the Bible that there's one for every day of the year, we are left with no excuse to be afraid. So when we find ourselves tempted to fear, let's reflect on those scriptures.
"See, the Lord your God has placed the land before you; go up, take possession, as the Lord, the God of your fathers, has spoken to you. Do not fear or be dismayed." Deuteronomy 1:21 (NAS)
When He sends you on a mission, He'll be with you through it.
"Then I said to you, 'Do not be shocked, nor fear them.'" Deuteronomy 1:29 (NAS)
Moses was recounting sending the people of Israel up against an enemy who was literally bigger than they were; unfortunately they forgot that their own God was bigger than their enemy. Let's remember that: God is bigger than any enemy!
"But the Lord said to me, 'Do not fear him, for I have delivered him and all his people and his land into your hand; and you shall do to him just as you did to Sihon king of the Amorites, who lived at Heshbon.'" Deuteronomy 3:2 (NAS)
Don't forget previous victories.
"Do not fear them, for the Lord your God is the one fighting for you." Deuteronomy 3:22 (NAS)
When you set out to do what God has for you to do, He is guaranteed to be working on your behalf.
"you shall not be afraid of them; you shall well remember what the Lord your God did to Pharaoh and to all Egypt:" Deuteronomy 7:18 (NAS)
You know the story of the ten plagues, and the Red Sea crossing. We're still serving that same God, and He hasn't gotten tired or run out of ideas.