Geshe Kelsang Gyatso said this quote

Without inner peace, outer peace is impossible. We all wish for world peace, but world peace will never be acheived unless we first establish peace within our own minds. We can send so-called 'peacekeeping forces' into areas of conflict, but peace cannot be oppossed from the outside with guns. Only by creating peace within our own mind and helping others to do the same can we hope to achieve peace in this world.

~ Geshe Kelsang Gyatso

Normally we divide the external world into that which we consider to be good or valuable, bad or worthless, or neither. Most of the time these discriminations are incorrect or have little meaning. For example, our habitual way of categorizing people as friends, enemies, and strangers depending on how they make us feel is both incorrect and a great obstacle to developing impartial love for all living beings. Rather than holding so tightly to our discriminations of the external world, it would be much more beneficial if we learned to discriminate between valuable and worthless states of mind.

~ Geshe Kelsang Gyatso