Good and Evil exist because of law; tree of knowledge of good and evil. Law defines what is not acceptable and what is acceptable, with fear and punishment used to help people avoid the evil defined by law.
For example, in the US, which has 50 states, marijuana laws differ from state to state. It is evil in some states and not evil in others depending on the state's laws. Evil is not innate but conditioned by law and its choice of enforcement.
The PC crowd may define prayer in schools as illegal and therefore evil, with punishment like suspension for daring to break the law. In this case, the true evil comes from those who are intolerant. But this will be called good, by the law. Law of man often conflict with laws of God. Laws of God; universal, defines fundamental principles of good and evil. Victimizing others for a victimless crime is worse than the victimless crime, even if the former is legal and called good, and the later is called evil; illegal.
Atheism actually have created more evil than religion since the laws of religion are older and come from a simpler time, so there are fewer laws. Atheism is more modern and through government and separation of church and state, non religions have added orders of magnitude of more laws of good and evil, thereby amplifying evil and good.
Addendum:
When the brain writes to memory, emotional tags are added to sensory content. Our memory has both feelings and content. Law is a unique form of memory that games the natural brain, in that it adds two conflicting emotional tags, one for good and one for evil. Law is like a two sided coin where both sides are implied by one thing. The natural brain will only add one tag at a time; good or evil. But law adds two tags, one for good and one for evil. The result is the unnatural induction of conflicting feelings.
As an example, if you are in a love/hate relationship, you cannot just come or go to end the circumstance. If you just loved or you just hated, then you would stay or leave; done. But with love-hate, you are attracted and repelled at the same time; stuck in orbit, unable to fully leave or fully stay.
In the case good and evil, the conflicting feelings creates a similar state of suspension; Jesus between two thieves. The good and evil defined by law are both thieves, in the sense that good comes with evil; one coin and two connected tags that conflict.
One solution is to repress the dark side; evil implied by law, and live by the good. However, since good and evil are two sides of the same coin, the repressed evil is still there but made unconscious; shadow side of the personality. The shadow side is sort of like an OAI; organic artificial intelligence. I call it the Satan subroutine. The brain can support virtual consciousness beyond the ego such as in multiple personality disorders, with the Satan subroutine a collective disorder; collective laws.
The Preacher may repress his dark side connected to bible law, only to become compelled to break the very laws he teaches. If his repression is strong, the OAI subroutine can become active, hoping to lower the potential by becoming conscious. This OAI subroutine is how evil seems to become innate after training.
Doing away with law and forgiveness of sin, was designed to help us stop adding conflicting emotional tags, thereby restoring the brain to one tag per memory, so we can come or go and not just orbit via OAI obsession. The latter can happen culture wide; OAI networking into social conflict and war.