And on that note...

"So powerful is the light of unity that it can illuminate the whole earth."
-Baha'u'llah

"Hate grows and victors where love is afraid to share its bloom."
-Don Williams, Jr.

"Cultural differences should not separate us from each other, but rather cultural diversity brings a collective strength that can benefit all of humanity."
-Robert Alan

"There are no nations! There is only humanity. And if we don't come to understand that right soon, there will be no nations, because there will be no humanity."
-Isaac Asimov

"Let us have but one end in view, the welfare of humanity; and let us put aside all selfishness in consideration of language, nationality, or religion."
-John Comenius

"I know there is strength in the differences between us. I know there is comfort where we overlap.”
-Ani DiFranco

"No man is an island, entire of itself; every man is a piece of the continent … any man's death diminishes me, because I am involved in mankind; and therefore never send to know for whom the bell tolls; it tolls for thee."
-John Donne

"A human being is a part of the whole that we call the universe, a part limited in time and space. He experiences himself, his thoughts and feelings, as something separated from the rest -- a kind of optical illusion of his consciousness. This illusion is a prison for us, restricting us to our personal desires and to affection for only the few people nearest us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living beings and all of nature."
-Albert Einstein

"Peace is not unity in similarity but unity in diversity, in the comparison and conciliation of differences."
-Mikhail Gorbachev

"All conflict is about difference; whether the difference is race religion, or nationality...Difference is of the essence of humanity. Difference is an accident of birth and it should therefore never be the source of hatred or conflict. The answer to difference is to respect it. Therein lies a most fundamental principle of peace: respect for diversity."
-John Hume

(Most of these quotes are from this site.)