The coming of Jesus made it possible for sinners in a dark sinful world to be brought into the light of fellowship with God. Everything the devil stands for is in opposition to this. The devil wants darkness, not light. The devil wants sin, not righteousness. The devil wants the lie, not the truth. The devil wants to keep people away from the joy of fellowship with God.
The reason the Son of God appeared was to destroy the works of the devil!
Pleased to Dwell, p194.