The poem "Enemies" by Wendell Berry:
If you are not to become a monster,
you must care what they think.
If you care what they think,
how will you not hate them,
and so become a monster
of the opposite kind? From where then
is love to come—love for your enemy
that is the way of liberty?
From forgiveness. Forgiven, they go
free of you, and you of them;
they are to you as sunlight
on a green branch. You must not
think of them again, except
as monsters like yourself,
pitiable because unforgiving.