NewChapter,
I didn't expect you to be able to give a good answer and to define evil. You haven't disappointed me. That's why the argument is so old.
When it comes to the problem of suffering and the existence of evil, at least a Theist can give some answer, but an Atheist can only give an answer such as:"In a world where there is no God what do you expect?", "That is just the way it is", "Too bad", "That's just your bad luck" or "That's your problem". Fatalism is fine in theory, but in a suffering world the most atheism can offer to those who are being hurt is Bertrand Russell's "unyielding despair". (Blanchard, Does God believe in Atheists?, p551). There is no reason to anything, nor is there any justice; there is no God who is wise and loving and who has a plan; your suffering is meaningless, and you just have to get on with it. If you can't, then its just too bad.
What atheists reject is that belief in atheism is itself evil, even the greatest evil, because it opens the door to all other evils. This can be best illustrated by remembering the testimony of Richard Wurmbrand beingtortured and witnessing the torture of others in an Atheist prison in Romania:-
"What the communists have done to Christains surpasses... human understanding," wrote Wurmbrand. "I have seen communists whose faces while torturing believers shone with rapturous joy. They cried out while torturing the Christians, "We are the devil!" He called communism "a force of evil" that could only be countered by a greater spiritual force, "the Spirit of God." He added:
The communist torturers often [told me], "There is no god, no hereafter, no punishment for evil. We can do what we wish." I heard one torturer say, "I thank God in whom I don't believe, that I have lived to this hour when I can express all the evil in my heart." www.globalmuseumoncommunism.org/features/war_on_religion?page=2
The Roman Catholic Inquisition also indulged in torture, usually of Protestant believers. They also had no real faith in the God of the Bible, or love for Christ. Who can say they were really putting into practice the commands of Scripture or obeying the will of Christ? They were torturing Protestant believers because the Protestants were saying the Roman Catholic religion was not in accordance with Scripture.