Religions instill the idea that good and evil are absolutes, but this is false. Morality is relative and depends on the situation. Humans and animals follow the same rule: forest animals are cruel because the conditions of life in the forest demand it, domestic animals are kind because they always have enough to eat, but a large domestic dog may eat you if it be too much hungry and has no food to eat, this is exactly how humans manner in different situation.
Discussion
Wtf... I wouldn't become a savage animal just because I'm hungry.
It feels you are making the same argument as the socialists, saying that robbery exists because these people are poor and need to commit crimes in order to survive.
Saying that material conditions determine the immaterial like mind, wants and needs, thus causing them to act how they do. But since you already shown to be an atheist, being a materialist isn't that far.
Yes, I am a materialistic atheist and this is my opinion, you are free to agree with me or not.