St Nikolai of Zicha:
I repent for all the slayers of men, who take the life of another to preserve their own. Forgive them, Most Merciful Lord, for they know not what they do. (Luke 23:34) For they do not know that there are not two lives in the universe, but one, and that there are not two men in the universe, but one. Ah, how dead are those who cut the heart in half!
source: Fr Stephen Freeman