Martin Luther King Jr. (1929-1968) was an American minister best known for his contributions to the civil rights movement in the United States. The rest of this post is some quotes from King.
Mutual understanding
"Every word and deed must contribute to an understanding with the enemy and release those vast reservoirs of goodwill which have been blocked by impenetrable walls of hate." (Loving Your Enemies, Christmas 1957)
"The strong man holds in a living blend strongly marked opposites... The philosopher Hegel said that truth is found neither in the thesis nor the antithesis, but in the emergent synthesis which reconciles the two." (Strength to Love, 1963)
"...I am convinced that men hate each other because they fear each other. They fear each other because they don't know each other and they don't know each other because they don't communicate with each other and they don't communicate with each other because they are separated from each other. And God grant that something will happen to open channels of communication, that something will happen because men of goodwill will rise to the level of leadership." (Address to Cornell College, 1962)