"God is evil, so I don't really care if I offend Him. He offends me."
As an atheist are you saying that He's real? Check out Romans 8:7 for why He is offensive to you.  It will show you your core motive.
Note:  “Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be” (Romans 8:7).