Compare the boundaries between ethical/inethical killing with or without the notion of God.?

Answer 1

To make this easy for me, I'll stick with human on human, nothing more.
Ethical killing is for protection, like self-defense or the defense of a country.
Unethical killing is killing for personal reasons such as anger, jealousy, and personal power.

Answer 2

Very difficult question to answer easily. My short sweet dial-up answer is this-
Ethics by definition are baised on morality and commonly accepted concept of good and evil.
In essence, ethics have to be baised on a society and therefore the religion or religions that society is formed on.
Without a god or society- one mans perception, and his concept of survival are the only dictators of doctrine. I tend to think that death is inevitable, and not necisarily connected to right, wrong or otherwise. Personally I have killed and will kill as I see fit
and right, day to day, learning as I go with some regret and some joy.

Answer 3

Why would you have to kill someone who is attacking you? All that is required in such a situation is to immobilize the threat and get away. To take the extra step and actually kill the threat is unnecessary, and unethical.