Yes, evil does exixst but end of the day it depends on how strong a person can control the evilness in their heart and the type of environment the person grew up in.
I'm going to take a very relative point of view on this. Yes, evil exists, but not in an independent and strictly set sense. Although it's tempting (and to some extent carved into human nature), evil should not be defined as one thing or another. Doing so only gives rise to moral dilemmas and forces a need for an utilitarian approach to life. We can't say that murder is evil, for claiming so gives birth to the moral dilemma of killing a hundred to save a thousand. We cannot say theft is evil, for that gives rise to the moral dilemma of whether or not to steal a scientist's Death Star plans to save millions. Alternately we cannot claim lying is bad, for it gives rise to the moral dilemma of whether or not one should lie to a friend about his cancer to keep him happy enough so that he would not commit suicide. I suggest reading Nietzsche for a better explanation of some depth, in particular section 201 where he claims that So as a quick wrap-up, evil can to some extent exist, but not as a set rule of black-and-white divisions and definitions, but rather what society needs and does not need to develop and progress as a whole which is forever ephemeral and changing.
^ But that's more about a just man and an unjust man... I just finish reading that book before the holiday.. Plato: Republic ^^
I think evil DOES exist. Because if you think about it, If there was no Evil then there will be NO WAR! No racism, No poor people
but you can have only light space (thinking of the Big Bang explosion) and only dark space (thinking of the "dark matter" stuff)