Sex is evil, because it creates life, and all life is evil.
Apathy is evil, because ignoring the plight of your fellow man is evil.
Taking life is not evil, but the way in which you take it is. Taking life in apathy is evil. Sometimes taking life is necessary to avoid apathy, like euthanasia.
So, how did you come to this conclusion that all life is evil because all life is selfish?
Surely, some people are selfish, more or less, and some people are evil, more or less, but you can't generalize in this way.
Many people like Mother Theresa, or jesus in the past, was completely unselfish, and gave everything to others.
I worry about this statement you just wrote: Taking life is not evil because if we accept this, we justify killing.
Life is God's gift and blessing, not something we own and we are not free to do with it as we wish.