The point is, what defines good and what defines evil.
I use reason and logic. And a few rules that reason and logic provide. Like The Golden Rule which is an ethical code that states that one has a right to just treatment and a responsibility to ensure justice for others.
Or the Platinum Rule: treat others the way they want to be treated.
Or would you rather have "good" and "evil" defined externally? Via a revelation? From a psychotic tyrant that condemns "his" people to eternal suffering for simply disbelieving in him (on the other hand he can forgive just about anything else - rape, murder, genocide ...)?
The main point is that there are no moral absolutes because moral absolutes are potentially evil.
This is why:
"... the lesson of today's terrorism is that if God exists, then everything, including blowing up thousands of innocent bystanders, is permitted - at least to those who claim to act directly on behalf of God, since, clearly, a direct link to God justifies the violation of any merely human constraints and considerations. In short, fundamentalists have become no different than the "godless" Stalinist Communists, to whom everything was permitted since they perceived themselves as direct instruments of their divinity, the Historical Necessity of Progress Toward Communism."