For we are the aroma of Christ to God among those who are being saved and among those who are perishing, to one a fragrance from death to death, to the other a fragrance from life to life.
2 Corinthians 2:15-16a
This is a fairly succinct explanation of why those who follow Satan hate those who follow Christ. The Christians are a constant reminder to the non-christians that they are on a path of destruction leading only to ultimate destruction.