Stated very simply, I face reality and admit that not only isn’t there anyone at home upstairs, there isn’t even any upstairs. I have one life and I intend to make the most of it. Therefore it follows naturally that if I firmly believe this, why then I cannot deprive another person of their turn at existence. Only the very self-assured political and religious zealots kill people in order to save them.
It takes a real shallow thinker to claim that atheism has no consequences. It actually says that there is no escaping the consequences — you aren’t going to get a lollipop in heaven if you say the right words on your deathbed. You have one life and you have to live with it, and then you die, and there are no take-backs or resurrections or rewards or punishments.