Now this is what the LORD says—He who created you, O Jacob, and He who formed you, O Israel: “Do not fear, for I have redeemed you; I have called you by your name; you are Mine! — Isaiah 43:1
The command'fear not' is anchored in a past-tense reality: I have redeemed you. God isn't asking you to work up courage; He's telling you to look at what He's already done. He blots out your transgressions like a cloud and your sins like a mist. You were redeemed not with corruptible things like silver or gold, but with the precious blood of Christ. My Father, who gave you to Me, is greater than all, and no one can snatch you out of His hand.