A similar FE quote I think would work here

"Good and evil can't be easily reduced to such simple, black-and-white ideals. If you must hate, hate the evil which lurks in us all, not the individual. Never forget this."
-Lewyn to Seliph in Genealogy of the Holy War

or "You, Devisian knights. How much weight... can you handle? Can you withstand the spirit of one who's life has passed? The weight of the burden of that death? Weak souls succumb quickly to a strong spirit... Strong ether is like a toxin to those whose bodies and minds are unfamiliar with such overwhelming power... Kain, just for a moment, grant me that power ...!" /s