Fear is one of the primary weapons of the enemy. Fear is the opposite of faith in God. It is actually faith in Satan. As Christian disciples we need to reject fear. It should have no place in our walk with Jesus.
Here is the good news:
For God hath not given us the spirit of fear; but of power, and of love, and of a sound mind. (2 Timothy 1:7)
Satan is the one who causes us to fear. How do we counteract it? The Apostle John tells us:
There is no fear in love, but perfect love casts out fear; for fear has to do with punishment, and whoever fears has not reached perfection in love. (1 John 4:18)
Jesus has taken all our punishment on the cross:
Surely he has borne our infirmities
and carried our diseases;
yet we accounted him stricken,
struck down by God, and afflicted.
But he was wounded for our transgressions,
crushed for our iniquities;
upon him was the punishment that made us whole,
and by his bruises we are healed. (Isaiah 53:4-5)
Let fully comprehend the perfect love of God. God has given his all to us. He has held back nothing, not even his only eternal Son. His Son has died for our sins. Therefore, we no longer have to die for them.
Jesus did more than die, he rose again from the dead, triumphing over hell, sin, and the grave:
This grace was given to us in Christ Jesus before the ages began, but it has now been revealed through the appearing of our Savior Christ Jesus, who abolished death and brought life and immortality to light through the gospel. (2 Timothy 1:9-10)
It is true that flesh and blood must die, but Jesus has shown us by his resurrection that we, too, will be raised to life eternal:
Since therefore the children share in flesh and blood, he himself likewise partook of the same things, that through death he might destroy the one who has the power of death, that is, the devil, and deliver all those who through fear of death were subject to lifelong slavery. (Hebrews 2:14-15)
We no longer need to fear death. Death is just a passing to life forever more:
When this perishable body puts on imperishability, and this mortal body puts on immortality, then the saying that is written will be fulfilled:
“Death has been swallowed up in victory.”
“Where, O death, is your victory?
Where, O death, is your sting?” (1 Corinthians 15:54-55)
In some cases, fear can be a spirit that the enemy has placed upon us without our awareness. If fear is persistent, it is probably a spirit. We can be delivered from this spirit. We have authority in Christ to cast it out. A prayer of agreement with someone else is helpful.