No, the enemy is disunion from God. 

Fear is a mere emotion. 

Fear may cause disunion from God, our letting emotions run lead us around by the nose. 
Sin really is a deliberate act of disunion with God. 
Disobeying the commandments does is an act of disunion with God. 
Pride = disunion.
Vanity = disunion.
Nursing resentment = disunion. 
Love of sensuality (all forms) - putting your security in the material/sense world is an act of disunion. 

All of these acts cause a disordering in us of our orientation toward God, and thus injures our union with Him. 

Pray is an act of union with God.
Setting aside our pride out of love of God is an act of union with God.
Approaching reconciliation with a sincere desire to begin again (with God) is an act of union with God.

Communion.