If you can’t be just to one person, you can’t also be just to the rest. – itakeoffthemask
Morality, true morality is not like politics. It is not a morality of numbers where one could easily sacrifice a few for the good of all the others, for the good of the rest.
One soul is not just one person. One soul is a whole universe of significance in itself. You do not kill that soul so you can save other souls. The moment you are able to murder one soul, you can easily get rid of the rest.