In Isaiah 43:1 the Lord makes this grand and encouraging statement to His people "Fear Not." Now why has our God instructed His people not to fear? Because we as frail and sinful creatures of the dust are so prone to fear. We have plenty of reason to fear left to ourselves. We are utterly sinful and God with whom we have to do is infinitely) HOLY. From this scripture we can find several comforting reasons why God has told believers not to fear.
The church of the Lord Jesus Christ is His creation. He chose a people in Christ before the foundation of the world to be His bride (2 Thes. 2:13). Everything the believer has before God is by His sovereign grace (I Cor. 1:30; 15:10). We are His workmanship created in Christ Jesus (Eph. 2:8-10). Fear not!
Our Lord Jesus paid the enormous price to effectually redeem the people that were given to Him in eternity (I Peter 1:18-20). Because He fully paid our sin debt and satisfied God's justice there is no condemnation to those who are in Him (Romans 8:1). Therefore, we have good reason not to fear.
God is intimately acquainted with all His people. He has always known their names and will in His own purpose and grace irresistibly call them to Christ in faith (Jn. 10:3). Fear not!
His people are a created people, a redeemed people, a called people but they also are a tried people, but they will never be a forsaken people. The Great Shepherd will provide and protect the sheep (Psalm 23:1). "If God be for us, who can be against us?" Read the blessed promise in John 16:33. Fear not!
Our God is in Sovereign control of all things (Rom.11:33-36). He is both the Just God and the Justifier of all those who look to Him alone for salvation (Isa. 45:21-22). Since Christ Jesus is God, He has infinite ability to save His people from all their sins (Heb. 7.25). None for whom Christ died will ever perish in their sins (Matt. 1:21).