"But the Lord is faithful; he will strengthen you and guard you from the evil one." (2 Thessalonians 3:3 NLT) .
The Bible is filled with the injunction, "Fear not". David affirmed, "Yea though I walk through the valley of the shadow of death, I fear no evil" (Psa 23:4). I like to believe that the above passage is the reason why God commands us not to fear.
God is faithful! Faithfulness means you can trust someone to do their part of an agreement or arrangement. Faithfulness means you can count on someone to keep their word. Faithfulness means you can rely on someone and not have any reason to regret it. That is what God is for us... faithful. Now if you have someone like that on your side do you have any reason to be scared especially when He has already promised that He will protect you against all.
God will strengthen you when you are weak, down and scared. And what's more important is that He will keep you from the evil one. That means no matter how loud the evil threatens, it won't get to you. You are absolutely protected. So don't be scared.