from Martin Luther King Jr.

Darkness cannot drive out darkness;
 only light can do that. Hate cannot drive out hate;
 only love can do that. 

Have we not come to such an impasse in the modern world
 that we must love our enemies - or else? 
The chain reaction of evil - hate begetting hate,
 wars producing more wars - must be broken,
 or else we shall be plunged into the dark abyss of annihilation. 

I believe that unarmed truth and unconditional love
 will have the final word in reality. This is why right,
 temporarily defeated, is stronger than evil triumphant. 

I have decided to stick with love.
 Hate is too great a burden to bear. 

Love is the only force capable of transforming
 an enemy into friend. 

We must develop and maintain the capacity to forgive.
 He who is devoid of the power to forgive is devoid 
of the power to love. There is some good in the worst of us
 and some evil in the best of us. When we discover this,
 we are less prone to hate our enemies. 

~ Martin Luther King Jr.