Man does not do evil for evil's sake.
FACT
Some German and British soldiers of world war 2 reported that killing is able to make fun. In war it's possible someone kills only on reason it makes fun to kill. In such a situation everyone is able to do evil for evils sake.
What does that have to do with anything?
You said "man doesn't do evil for evil's sake." I showed to you that this sentence finds not a full representation in the reality. I think everyone is able to come in war into the situation to kill just for fun. I'm not sure now - but did Vietnam veterans not report about similar problems?
Man has free will to do good or not do good.
But no one has a free will to recognize what's good or not good. Lots of people think for example to say
"right or wrong, my country" is an honorful thing - but indeed it is criminal to say so. ("Right or wrong, my country" = I'm not sure it is good what I do, but I do not care about good and evil as longs as I do what I do for my country.)
Those guys did not do evil for evil's sake. The did "evil" for the sake of their own selfish good; their enjoyment.
No. They did not go to war, because they loved it to go to war. They noticed how the war changed their psychological structure and they did not like to live with lies - as you do now, because you on your own - like everyone else - could be one of them.
And what you say here on pieces of electronic paper is not this, what you are doing on your own. If everything what god creates is always only good then you would not try to change anyones opinion - independent how evil or absurde this opinion is. And I fear exactly this is the brainwashing background to say so. Such ideas eliminate critics. And Christians never said so. God created the devil for example. Jesus was injust, when he damned a fig tree for example. Jesus said in another context "Don't call me good" and so on. You perception is selective. And you don't see that god has many, many, many children - and he is the father of them all.