Whoever continues to sin belongs to the Devil, because the Devil has sinned from the very beginning. The Son of God appeared for this very reason to destroy the works of the devil." (1 John 3:8)

In the spiritual battle, we have one true enemy who we must fight and reject completely - the Devil.  Theophan writes:

"Finally, look at sin from the point of view of the devil, who was its first creator and propagator, and see for whom you work by sinning. God has done and will do everything for you, but you do not want to please Him. The devil has done nothing for you, only tyrannizes you with sin, but you willingly and indefatigably work for him. You befriend him through sin, and he does evil to you through it. He entices you to sin by promising its sweetness, but those who fall into sin he torments and tortures. Here he convinces you that your sins are nothing, but there he will present them to your reproach, as major points. He trembles with evil joy when someone falls into nets of sin and gets stuck in them. Realize all this and arouse yourself to hatred for this man-hater and all his works. When you will thus press into your heart one after another contrition-producing and softening feelings — horror and fear, sorrow and regret, repugnance and hatred of sin — little by little your heart will warm up and begin to move, and after it your enfeebled will will begin to strain itself and spring into action. As volts of electricity communicate a certain tension and stimulation to the body, or as the cool, clean morning air communicates freshness and energy, so does this feeling that fills the soul awaken slumbering energy and renew the call and willingness to escape your dangerous condition. These will be the beginnings of your active care for your own salvation. Rush decisively this very instant."

"Whoever continues to sin belongs to the Devil, because the Devil has sinned from the very beginning. The Son of God appeared for this very reason to destroy the works of the devil." (1 John 3:8)